Free variance calculator. Calculate sample variance (÷n−1) or population variance (÷n), coefficient of variation (CV%), and variance percentage (% change between two numbers) — with complete step-by-step working for each
Free margin of error calculator. Find MOE from sample statistics or proportions using MOE = z*(or t*) × standard error, build a confidence interval, or solve the required sample size for a target margin of error — with full step-by-step working
Free standard error calculator. Calculate the standard error of the mean (SEM = s/√n) or the standard error of estimate for regression (SEE = √(SSres/(n−k−1))) with complete step-by-step working
Free critical value calculator for t, z, and chi-square distributions. Find t critical values, z critical values, and chi-square critical values instantly with confidence level or alpha input, step-by-step working, and printable reference tables
Free t-test calculator for one-sample, two-sample (independent), and paired t-tests. Get the t statistic, degrees of freedom, p-value, critical value, and a clear reject/fail-to-reject decision with full step-by-step working.
Free polar to rectangular calculator. Convert polar coordinates (r,θ) to rectangular (x,y) and back — with step-by-step working, quadrant-correct atan2 handling, complex number form, and degree/radian toggle
Free zeros of a function calculator. Find all real and complex zeros of any polynomial — quadratic formula shown explicitly, cubic equation solver with discriminant, zero product property tool, and full step-by-step working
Free fraction decomposition calculator. Enter any rational function P(x)/Q(x) and get the full partial fraction decomposition with step-by-step working — distinct roots, repeated roots, and irreducible quadratic factors
Free points of inflection calculator. Find inflection points using the second derivative test with full sign-change verification, concavity intervals, and complete step-by-step working. Not just root-finding — genuine concavity change confirmed.
Free initial value problem calculator. Solve first and second order linear ODEs with constant coefficients — general solution, particular solution, and complete step-by-step working using the characteristic equation method