Psychrometric Calculator | Wet Bulb & Dry Bulb Temperature Calculator

Q: What is wet bulb temperature?

Wet bulb temperature is the lowest temperature achievable by evaporating water into air at constant pressure. It is measured with a thermometer that has a moistened wick around its bulb. As water evaporates, it cools the thermometer below the standard air (dry bulb) temperature. It is always equal to or less than dry bulb temperature, and is used to calculate relative humidity and other psychrometric properties.

Q: How do you calculate relative humidity from wet and dry bulb temperature?

Use the Sprung psychrometer equation: (1) Calculate saturation vapor pressure at dry bulb: es = 0.6108 × exp((17.27 × Td) / (Td + 237.3)), (2) Calculate actual vapor pressure: ea = ew - 0.000799 × P × (Td - Tw), where ew is saturation pressure at wet bulb, (3) Calculate RH = (ea / es) × 100%.

Q: What is the difference between wet bulb and dry bulb temperature?

Dry bulb temperature is standard air temperature measured by a shielded thermometer. Wet bulb temperature is always lower because evaporation from a moistened wick cools the thermometer. The difference (wet bulb depression) indicates air dryness. At 100% relative humidity they are equal because no evaporation can occur.

Q: What is a psychrometric chart used for?

A psychrometric chart allows determination of all moist air properties from two known values. It shows saturation curves, constant RH lines, wet bulb lines, and enthalpy lines. HVAC engineers use it for air conditioning design and cooling tower calculations. Meteorologists use it for atmospheric analysis and fog prediction.

Q: How do you find dew point from wet bulb temperature?

Calculate RH from wet and dry bulb temperatures using the Sprung equation, then use the Magnus inverse formula: gamma = ln(RH/100) + (17.625 × T)/(243.04 + T), and dew point = (243.04 × gamma)/(17.625 - gamma). On a psychrometric chart, plot your condition and trace horizontally left to the saturation curve.

Q: What does 100% relative humidity mean?

100% relative humidity means the air is fully saturated and cannot hold more water vapor at that temperature. Dry bulb, wet bulb, and dew point temperatures are all equal. Any further cooling causes condensation, forming fog, dew, or clouds.

Q: Why is wet bulb temperature always lower than dry bulb temperature?

Evaporation is endothermic — it absorbs heat from the wet thermometer bulb, lowering its temperature. The drier the air, the faster evaporation occurs and the greater the cooling. Only at 100% RH do they equalize because no evaporation can occur in saturated air.

Q: What is wet bulb depression?

Wet bulb depression is the difference between dry and wet bulb temperatures. It indicates air dryness: 0°C = 100% RH, 1-3°C = high humidity (70-95%), 4-7°C = moderate (40-70%), 8-12°C = low (20-40%), 13°C+ = very dry (under 20% RH).

Q: How accurate is a wet and dry bulb psychrometer?

A properly used Assmann psychrometer achieves plus or minus 2% RH accuracy in the 20-90% RH range. Key factors are clean muslin wick, distilled water, adequate airflow (minimum 3 m/s), 2-3 minutes stabilization time, and shielding from direct sunlight.

Q: What is the formula for relative humidity?

RH (%) = (ea / es) × 100, where ea is actual vapor pressure and es is saturation vapor pressure. The Magnus formula gives es = 0.6108 × exp((17.27 × T) / (T + 237.3)) in kPa. From psychrometer readings, actual vapor pressure uses the Sprung equation: ea = ew - 0.000799 × P × (Td - Tw).

Wet Bulb Temperature Calculator — Complete Psychrometric Reference

This free wet bulb calculator determines relative humidity, dew point temperature, absolute humidity, specific humidity, enthalpy, and vapor pressures from any combination of wet bulb and dry bulb temperature measurements. As a full psychrometric calculator, it supports reverse calculations (RH to wet bulb), plots an interactive psychrometric chart with saturation curves and constant RH lines, and provides a comprehensive reference table for all temperature and humidity combinations.

What is Wet Bulb Temperature?

Wet bulb temperature is the lowest temperature that a surface can reach through evaporative cooling when water is evaporated into the surrounding air at constant pressure. It represents the thermodynamic wet-bulb temperature — the temperature at which the air becomes saturated if the process is adiabatic (no heat exchange with surroundings).

Unlike dry bulb temperature (standard air temperature), wet bulb temperature depends heavily on the moisture content of the air. When humidity is high, less evaporation occurs and the wet bulb reads closer to the dry bulb. When air is very dry, rapid evaporation cools the wet bulb thermometer significantly below the dry bulb reading.

Dry Bulb
Thermometer

Standard temperature reading — not affected by humidity

Wet Bulb
Thermometer

Moistened wick — cooled by evaporation

How a Psychrometer Works

A psychrometer (also called a wet-and-dry-bulb hygrometer) uses two thermometers mounted side by side. The dry bulb thermometer measures normal air temperature. The wet bulb thermometer has a clean muslin wick wrapped around its bulb, saturated with distilled water. As air passes over the wick, water evaporates — and the energy required for evaporation is drawn from the thermometer, cooling it below the air temperature.

Wet bulb depression = Dry bulb temperature - Wet bulb temperature
0°C depression = Air is 100% saturated (no evaporation possible)
Large depression = Very dry air (rapid evaporation, strong cooling)
Wet bulb is always = dry bulb — they are equal only at 100% RH

Real-World Uses of Wet Bulb Temperature

Weather forecasting: Wet bulb temperature is used to calculate heat stress index, predict fog formation, and assess precipitation type (rain vs snow)
HVAC engineering: Cooling tower design, air conditioning load calculations, and duct sizing all rely on wet bulb temperature
Agriculture: Assessing evapotranspiration rates, irrigation scheduling, and crop storage humidity requirements
Industrial drying: Spray dryers, food processing, pharmaceutical manufacturing all use wet bulb for process control
Climate science: Wet bulb temperature is increasingly used to measure extreme heat events and human survivability limits

Critical climate note: Scientists have identified a wet bulb temperature of 35°C (95°F) as the theoretical human survivability limit — above this threshold, the human body cannot cool itself through sweating regardless of fitness or hydration. This threshold is being approached in some regions during extreme heat events.

What is Relative Humidity?

Relative humidity (RH) is the ratio of the actual amount of water vapor present in the air to the maximum amount the air can hold at that temperature, expressed as a percentage. It describes how "full" the air is with moisture relative to its maximum capacity at current temperature.

Relative Humidity Formula: RH (%) = (Actual Vapor Pressure ÷ Saturation Vapor Pressure) × 100
RH (%) = (e_a ÷ e_s) × 100

Types of Humidity — Key Differences

Type	Definition	Units	Changes with Temp?
Relative Humidity	Ratio of actual to max vapor pressure × 100	%	Yes — rises as temp falls
Absolute Humidity	Mass of water vapor per unit volume of air	g/m³	No (constant moisture)
Specific Humidity	Mass of water vapor per mass of dry air	g/kg	No (constant moisture)
Humidity Ratio	Mass of water per mass of dry air (engineering)	kg/kg	No (constant moisture)

Why RH Changes With Temperature

Warm air can hold more water vapor than cool air (following the Clausius-Clapeyron relation). If you take a parcel of air with a fixed amount of water vapor and heat it, the saturation vapor pressure increases — but the actual vapor pressure stays the same — so RH decreases. This is why indoor air in winter feels dry: outdoor cold air with moderate RH is brought inside and heated, drastically reducing its relative humidity.

Example: Outdoor air at 5°C with 80% RH is heated to 22°C indoors. The actual vapor pressure stays the same, but the saturation pressure at 22°C is much higher — so the indoor RH drops to around 30%, causing dry skin, throat irritation, and static electricity.

RH and Human Comfort

Below 20%: Very dry — causes dry skin, chapped lips, increased infection risk from dried mucous membranes
20-40%: Dry — acceptable but slightly uncomfortable for extended periods
40-60%: Ideal comfort range — recommended by ASHRAE for occupied buildings
60-70%: Humid — feels sticky in warm conditions, mold risk begins
Above 70%: Very humid — promotes mold growth, dust mites, condensation on surfaces

Wet Bulb vs Dry Bulb Temperature — Complete Comparison

The dry bulb temperature is the standard air temperature measured with a regular thermometer shielded from moisture and radiation — what we normally mean when we say "it's 25 degrees." The wet bulb temperature is always lower than or equal to the dry bulb, and its proximity to the dry bulb tells us how much moisture the air is holding.

Property	Dry Bulb Temperature	Wet Bulb Temperature
Measures	Actual air temperature	Evaporative cooling temperature
Instrument	Shielded dry thermometer	Thermometer with wet muslin wick
Humidity effect	Not affected by humidity	Strongly affected — rises with RH
Always higher?	Yes — equal to wet bulb at 100% RH	No — always = dry bulb
At 100% RH	Equals wet bulb temperature	Equals dry bulb temperature
Used for	General temperature reading, comfort assessment	Humidity calculation, psychrometric analysis
On psychrometric chart	X-axis (horizontal)	Diagonal lines (sloping left to right)

Understanding Wet Bulb Depression

The wet bulb depression (dry bulb - wet bulb) is the single most important value for estimating air humidity from psychrometer readings:

Wet Bulb Depression Guide

0°C depression: RH = 100% (saturated air — fog, rain, or surfaces in direct contact with water)
1–3°C depression: RH = 70–95% (high humidity — tropical climates, after rain, near water bodies)
4–7°C depression: RH = 40–70% (moderate humidity — comfortable indoor conditions, temperate climates)
8–12°C depression: RH = 20–40% (low humidity — winter indoor air, semi-arid climates)
13°C+ depression: RH < 20% (very dry — desert conditions, dried industrial processes)

How to Calculate Relative Humidity from Wet and Dry Bulb Temperature

Here is the complete step-by-step method using the standard Sprung psychrometer equations:

Record your measurements Measure dry bulb temperature (T_d) and wet bulb temperature (T_w) using a calibrated psychrometer. Note atmospheric pressure P (use 101.325 kPa if unknown — standard sea level pressure).

Calculate saturation vapor pressure at dry bulb (Magnus formula) e_s = 0.6108 × exp((17.27 × T_d) / (T_d + 237.3)) [kPa]

Calculate saturation vapor pressure at wet bulb e_w = 0.6108 × exp((17.27 × T_w) / (T_w + 237.3)) [kPa]

Calculate actual vapor pressure (Sprung equation) e_a = e_w - 0.000799 × P × (T_d - T_w)
Where 0.000799 is the psychrometric constant for a ventilated (Assmann) psychrometer.

Calculate relative humidity RH = (e_a / e_s) × 100 [%]

Worked Example 1 (°C): T_d = 28°C, T_w = 21°C

Step 2: e_s = 0.6108 × exp((17.27 × 28) / (28 + 237.3)) = 0.6108 × exp(1.8228) = 0.6108 × 6.186 = 3.778 kPa

Step 3: e_w = 0.6108 × exp((17.27 × 21) / (21 + 237.3)) = 0.6108 × exp(1.4041) = 0.6108 × 4.072 = 2.487 kPa

Step 4: e_a = 2.487 - 0.000799 × 101.325 × (28 - 21) = 2.487 - 0.566 = 1.921 kPa

Step 5: RH = (1.921 / 3.778) × 100 = 50.8%

Worked Example 2 (°F): T_d = 85°F, T_w = 72°F

Convert first: T_d = (85 - 32) × 5/9 = 29.44°C, T_w = (72 - 32) × 5/9 = 22.22°C

Step 2: e_s = 0.6108 × exp((17.27 × 29.44) / (29.44 + 237.3)) = 4.078 kPa

Step 3: e_w = 0.6108 × exp((17.27 × 22.22) / (22.22 + 237.3)) = 2.657 kPa

Step 4: e_a = 2.657 - 0.000799 × 101.325 × (29.44 - 22.22) = 2.657 - 0.584 = 2.073 kPa

Step 5: RH = (2.073 / 4.078) × 100 = 50.8%

Psychrometric Chart Calculator — How to Read a Psychrometric Chart

A psychrometric chart is a graphical representation of the thermodynamic properties of moist air. Engineers, HVAC technicians, and meteorologists use it to determine all air properties from just two known values. Our interactive psychrometric chart calculator above draws your exact air condition as a point on the chart — with all key reference lines visible.

Key Components of a Psychrometric Chart

X-axis (horizontal): Dry bulb temperature (typically 10°C to 50°C or 50°F to 120°F)
Y-axis (vertical): Humidity ratio in g water per kg dry air (0 to 30 g/kg)
Saturation curve (100% RH): The curved outer boundary — left of this line is impossible (liquid water would form)
Constant RH lines: Curves running parallel to the saturation curve — labeled 10%, 20%, ... 90%
Wet bulb lines: Diagonal lines sloping from upper-left to lower-right — represent constant wet bulb temperature
Enthalpy lines: Nearly parallel to wet bulb lines — represent constant total heat content
Dew point: Found by tracing horizontally left from your condition point to the saturation curve

How to Locate Your Point on a Psychrometric Chart

Example: Dry bulb = 30°C, Wet bulb = 22°C

Find 30°C on the horizontal axis (x-axis)
Draw a vertical line upward from 30°C
Find the wet bulb diagonal line labeled 22°C
Your air condition is at the intersection of these two lines
Read humidity ratio on the y-axis by tracing horizontally: approximately 11.5 g/kg
Identify which RH curve passes through this point: approximately 47%
Trace left horizontally to the saturation curve to find dew point: approximately 18.4°C

Use Tool 3 (Psychrometric Chart tab) above to instantly plot your conditions. Enter dry bulb 30°C and wet bulb 22°C, then click "Draw Chart" to see the exact point plotted with all reference curves visible.

Dry Bulb Wet Bulb Temperature Chart

The following reference chart shows relative humidity values for common combinations of dry bulb temperature and wet bulb depression. This is the standard "dry bulb wet bulb temperature chart" used by meteorologists, HVAC technicians, and agricultural professionals worldwide.

Dry Bulb (°C)	Depression 1°C	Depression 2°C	Depression 3°C	Depression 5°C	Depression 7°C	Depression 10°C
10°C	88%	76%	65%	43%	23%	—
15°C	90%	80%	71%	52%	34%	8%
20°C	91%	83%	74%	58%	43%	19%
25°C	92%	85%	77%	63%	50%	28%
30°C	93%	86%	79%	66%	55%	35%
35°C	94%	87%	81%	69%	58%	40%
40°C	94%	88%	82%	71%	61%	44%

Notice that the same wet bulb depression produces different RH values at different dry bulb temperatures — this is because the saturation vapor pressure is temperature-dependent. At higher temperatures, a given wet bulb depression represents a smaller fraction of the total evaporative capacity, so RH is higher.

Use Tool 5 (Reference Chart tab) above for a complete interactive table with all depression values from 1°C to 10°C, switchable between °C and °F, with color-coded cells — green (high RH), yellow (moderate), orange (low).

Worked Examples — Psychrometric Calculations

Example 1: Calculate RH from Wet and Dry Bulb

Dry bulb = 30°C, Wet bulb = 22°C, P = 101.325 kPa

e_s(30°C) = 0.6108 × exp(17.27×30/267.3) = 4.243 kPa

e_w(22°C) = 0.6108 × exp(17.27×22/259.3) = 2.644 kPa

e_a = 2.644 - 0.000799 × 101.325 × 8 = 2.644 - 0.648 = 1.997 kPa

RH = (1.997/4.243) × 100 = 47.1%

Dew point = 18.4°C

Example 2: Find Wet Bulb from RH (Reverse Calculation)

Dry bulb = 25°C, RH = 60%, P = 101.325 kPa

Target: Find T_w such that the Sprung formula gives RH = 60%

Using bisection method starting from dew point (16.7°C) to dry bulb (25°C)

After 10 iterations: T_w = 19.4°C

Verification: e_w(19.4°C) = 2.249 kPa, e_a = 2.249 - 0.000799×101.325×5.6 = 1.797 kPa, e_s(25°C) = 3.168 kPa, RH = 1.797/3.168 × 100 = 56.7% ˜ 60% ?

Example 3: Find Dew Point

T = 20°C, RH = 65%

? = ln(65/100) + (17.625 × 20)/(243.04 + 20)

? = -0.4308 + 352.5/263.04 = -0.4308 + 1.3401 = 0.9093

T_dew = (243.04 × 0.9093)/(17.625 - 0.9093) = 221.01/16.716 = 13.2°C

Example 4: What does depression of 5°C mean?

Dry bulb = 27°C, Wet bulb = 22°C, Depression = 5°C

e_s(27°C) = 3.567 kPa, e_w(22°C) = 2.644 kPa

e_a = 2.644 - 0.000799 × 101.325 × 5 = 2.644 - 0.405 = 2.239 kPa

RH = (2.239/3.567) × 100 = 62.8%

A 5°C depression indicates moderate-to-humid air — comfortable indoor conditions.

Example 5: Calculate Absolute Humidity

Dry bulb = 28°C, Wet bulb = 21°C

From Example 1: e_a = 1.921 kPa, RH = 50.8%

AH = (216.7 × e_a) / (T + 273.15)

AH = (216.7 × 1.921) / (28 + 273.15) = 416.3 / 301.15 = 13.82 g/m³

Example 6: Convert Wet Bulb °C to °F

Wet bulb = 18°C ? °F = (18 × 9/5) + 32 = 32.4 + 32 = 64.4°F

Note: If dry bulb = 25°C (77°F) and wet bulb = 18°C (64.4°F), the depression = 7°C = 12.6°F

Example 7: RH when wet bulb equals dry bulb

When T_w = T_d: Depression = 0°C

e_a = e_w - 0.000799 × P × 0 = e_w

Since e_w = e_s (both at same temp): RH = (e_a/e_s) × 100 = 100%

Example 8: Calculate Enthalpy

Dry bulb = 25°C, RH = 60%

e_s(25°C) = 3.169 kPa, e_a = 3.169 × 0.60 = 1.901 kPa

W = 0.622 × 1.901 / (101.325 - 1.901) = 1.183 / 99.424 = 0.01190 kg/kg

h = 1.006 × 25 + 0.01190 × (2501 + 1.86 × 25)

h = 25.15 + 0.01190 × 2547.5 = 25.15 + 30.32 = 55.47 kJ/kg

Example 9: Calculate Wet Bulb Without Psychrometer

If you know dry bulb temperature and relative humidity, use the iterative bisection method (Tool 2 above).

For T_d = 30°C, RH = 50%: Dew point ˜ 18.4°C (lower bound), dry bulb 30°C (upper bound)

Bisection converges to T_w ˜ 22.0°C after approximately 12 iterations

Example 10: Using the Psychrometric Chart

Given: Dry bulb = 35°C, Relative Humidity = 40%

Locate 35°C on x-axis, draw vertical line
Follow the 40% RH curve — it intersects the vertical line at your condition point
Read y-axis: Humidity ratio ˜ 14.4 g/kg
Trace horizontally left to saturation curve: Dew point ˜ 20.0°C
Follow wet bulb diagonal through condition point: Wet bulb ˜ 24.0°C

Frequently Asked Questions

What is wet bulb temperature?

Wet bulb temperature is the lowest temperature achievable by evaporating water into air at constant pressure. It's measured with a thermometer that has a moistened wick around its bulb — as water evaporates, it cools the thermometer below the standard air (dry bulb) temperature. The wet bulb temperature is always equal to or less than the dry bulb temperature, and the two are equal only when air is 100% saturated. It is used alongside dry bulb temperature to calculate relative humidity, dew point, and other psychrometric properties.

How do you calculate relative humidity from wet and dry bulb temperature?

Use three steps: (1) Calculate saturation vapor pressure at dry bulb: e_s = 0.6108 × exp((17.27 × T_d) / (T_d + 237.3)), (2) Calculate actual vapor pressure using Sprung formula: e_a = e_w - 0.000799 × P × (T_d - T_w), where e_w is saturation pressure at wet bulb, (3) Calculate RH = (e_a / e_s) × 100%. Our wet bulb calculator performs all these steps automatically with full working shown.

What is the difference between wet bulb and dry bulb temperature?

Dry bulb temperature is the standard air temperature measured by a regular shielded thermometer — what weather forecasts report. Wet bulb temperature is lower because evaporation from a moistened wick cools the thermometer. The difference (wet bulb depression) directly indicates air dryness: small gap = humid air, large gap = dry air. At 100% relative humidity they are equal because saturated air cannot absorb more moisture, so no evaporation — and no cooling — occurs.

What is a psychrometric chart used for?

A psychrometric chart allows engineers and scientists to determine all thermodynamic properties of moist air from just two known values — typically dry bulb temperature and either wet bulb temperature or relative humidity. It shows saturation curves, constant RH lines, wet bulb lines, and enthalpy lines. HVAC engineers use it to design air conditioning systems, calculate cooling tower performance, and determine air treatment processes. Meteorologists use it to analyze atmospheric conditions and predict fog and precipitation formation.

How do you find dew point from wet bulb temperature?

First calculate relative humidity from wet and dry bulb temperatures using the Sprung equation. Then use the Magnus inverse formula: ? = ln(RH/100) + (17.625 × T) / (243.04 + T), and dew point T_d = (243.04 × ?) / (17.625 - ?). On a psychrometric chart, plot your condition at the intersection of dry bulb and wet bulb lines, then trace horizontally left to the saturation curve — the temperature where you hit it is the dew point.

What does 100% relative humidity mean?

100% relative humidity means the air is fully saturated with water vapor and cannot hold any more at that temperature. At this point, dry bulb = wet bulb = dew point temperature. Any further cooling causes condensation — water vapor converts to liquid droplets, forming fog, dew, or clouds. 100% RH doesn't mean you can feel the moisture or see it — fog only forms when tiny droplets nucleate on particles. Humid air feels "heavy" and sticky at high temperatures because sweat evaporates slowly.

Why is wet bulb temperature always lower than dry bulb temperature?

Evaporation is an endothermic process — it absorbs energy (heat) from the surroundings. When water evaporates from the wet wick, it draws heat from the thermometer bulb, lowering its temperature reading. The drier the air, the faster evaporation occurs, and the greater the cooling effect. Only at 100% relative humidity does wet bulb equal dry bulb, because saturated air cannot accept more water vapor so no evaporation — and no cooling — occurs.

What is wet bulb depression?

Wet bulb depression is the numerical difference between dry bulb and wet bulb temperatures (T_dry - T_wet). It directly indicates how dry the air is: 0°C = 100% RH (saturated), 1-3°C = high humidity (70-95% RH), 4-7°C = moderate humidity (40-70% RH), 8-12°C = low humidity (20-40% RH), 13°C+ = very dry air (<20% RH). Wet bulb depression is the fundamental measurement from which all psychrometric calculations proceed.

How accurate is a wet and dry bulb psychrometer?

A properly used Assmann (aspirated) psychrometer achieves ±2% RH accuracy in the 20-90% RH range. Key accuracy factors: (1) Clean, unwashed muslin wick — replace regularly, (2) Use distilled water only, (3) Adequate airflow — minimum 3 m/s for sling psychrometers, forced air for Assmann type, (4) Allow 2-3 minutes for readings to stabilize, (5) Shield from direct sunlight and radiation, (6) Accurate atmospheric pressure reading. Below 20% RH and above 90% RH, accuracy decreases — electronic capacitive sensors may be more reliable at extremes.

What is the formula for relative humidity?

The fundamental formula is: RH (%) = (e_a / e_s) × 100, where e_a is actual vapor pressure and e_s is saturation vapor pressure. Saturation pressure uses the Magnus formula: e_s = 0.6108 × exp((17.27 × T) / (T + 237.3)) in kPa. From psychrometer readings, actual vapor pressure is calculated using the Sprung equation: e_a = e_w - 0.000799 × P × (T_d - T_w), where the constant 0.000799 applies to ventilated/Assmann psychrometers and 0.000799 is for unventilated sling types.

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Types of Humidity — Key Differences

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RH and Human Comfort

Wet Bulb vs Dry Bulb Temperature — Complete Comparison

Understanding Wet Bulb Depression

Wet Bulb Depression Guide

How to Calculate Relative Humidity from Wet and Dry Bulb Temperature

Worked Example 1 (°C): T_d = 28°C, T_w = 21°C

Worked Example 2 (°F): T_d = 85°F, T_w = 72°F

Psychrometric Chart Calculator — How to Read a Psychrometric Chart

Key Components of a Psychrometric Chart

How to Locate Your Point on a Psychrometric Chart

Dry Bulb Wet Bulb Temperature Chart

Worked Examples — Psychrometric Calculations

Example 1: Calculate RH from Wet and Dry Bulb

Example 2: Find Wet Bulb from RH (Reverse Calculation)

Example 3: Find Dew Point

Example 4: What does depression of 5°C mean?

Example 5: Calculate Absolute Humidity

Example 6: Convert Wet Bulb °C to °F

Example 7: RH when wet bulb equals dry bulb

Example 8: Calculate Enthalpy

Example 9: Calculate Wet Bulb Without Psychrometer

Example 10: Using the Psychrometric Chart

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Psychrometric Calculator | Wet Bulb & Dry Bulb Temperature Calculator

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Wet Bulb Temperature Calculator — Complete Psychrometric Reference

What is Wet Bulb Temperature?

How a Psychrometer Works

Real-World Uses of Wet Bulb Temperature

What is Relative Humidity?

Types of Humidity — Key Differences

Why RH Changes With Temperature

RH and Human Comfort

Wet Bulb vs Dry Bulb Temperature — Complete Comparison

Understanding Wet Bulb Depression

Wet Bulb Depression Guide

How to Calculate Relative Humidity from Wet and Dry Bulb Temperature

Worked Example 1 (°C): Td = 28°C, Tw = 21°C

Worked Example 2 (°F): Td = 85°F, Tw = 72°F

Psychrometric Chart Calculator — How to Read a Psychrometric Chart

Key Components of a Psychrometric Chart

How to Locate Your Point on a Psychrometric Chart

Dry Bulb Wet Bulb Temperature Chart

Worked Examples — Psychrometric Calculations

Example 1: Calculate RH from Wet and Dry Bulb

Example 2: Find Wet Bulb from RH (Reverse Calculation)

Example 3: Find Dew Point

Example 4: What does depression of 5°C mean?

Example 5: Calculate Absolute Humidity

Example 6: Convert Wet Bulb °C to °F

Example 7: RH when wet bulb equals dry bulb

Example 8: Calculate Enthalpy

Example 9: Calculate Wet Bulb Without Psychrometer

Example 10: Using the Psychrometric Chart

Frequently Asked Questions

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Worked Example 1 (°C): T_d = 28°C, T_w = 21°C

Worked Example 2 (°F): T_d = 85°F, T_w = 72°F