kDa Calculator — Convert Daltons to Kilodaltons & Estimate Protein Size
Convert between Da, kDa and MDa instantly, estimate protein molecular weight from amino acid count or gene length, and predict SDS-PAGE band position with a visual gel diagram
biology
Biodiversity Index Calculator — Shannon, Simpson & Species Richness
Free biodiversity calculator — compute Shannon-Wiener diversity index (H’), Simpson’s index (1−D), species richness (S), and Pielou’s evenness (J) from species count data. Full step-by-step working shown
Isoelectric Point Calculator — pI from Protein or Peptide Sequence
Free isoelectric point calculator. Calculate pI from any protein or peptide sequence, view the charge vs pH curve, compute net charge at any pH, and use the MCAT pI formula with step-by-step working
Protein Molecular Weight Calculator — MW from Sequence in kDa
Free protein molecular weight calculator. Calculate exact protein MW from amino acid sequence in Da and kDa, monoisotopic mass, molar extinction coefficient ε₂₈₀, and amino acid composition with step-by-step working
Chi-Square Calculator — Goodness of Fit, Test of Independence & Critical Values
Free chi-square calculator — run goodness of fit tests and tests of independence with full (O−E)²/E working tables, p-values, critical values, and Cramér’s V effect size. Supports contingency tables up to 6×6
Hardy-Weinberg Calculator — Allele & Genotype Frequency Solver with Steps
Free Hardy-Weinberg calculator. Solve p, q, p², 2pq, q² from any known value — recessive phenotype frequency, allele frequency, or observed counts — with complete step-by-step working. Includes genotype frequency calculator, allele frequency calculator, and phenotype frequency calculator
Punnett Square Calculator – Free Generator for Mono, Di, Tri & Quadhybrid Crosses
Free Punnett square calculator and generator. Create 2×2 monohybrid, 4×4 dihybrid, 8×8 trihybrid, and 16×16 quadhybrid crosses instantly. Includes ABO blood type, X-linked, and special cross modes with step-by-step results
DNA Molecular Weight Calculator – MW, Concentration, A260/280 Purity & Base Counter
Free DNA molecular weight calculator compute MW from sequence or length, convert between ng/µL, nM, and pmol, calculate DNA concentration and purity from A260/A280 spectrophotometer readings. Supports dsDNA, ssDNA, and RNA
Reverse Complement Calculator – DNA & RNA Sequence Tool
Free reverse complement calculator for DNA and RNA sequences. Find the complement, reverse, and reverse complement instantly. Supports IUPAC ambiguity codes, FASTA input, GC content, palindrome detection, and DNA-to-mRNA transcription
How Big Will My Puppy Get: Dog Size and Weight Calculator
Predict your puppy’s adult weight and size category based on breed, current weight, and age