Free product rule calculator — find d/dx[u·v] = u’v + uv’ with full step-by-step working. Handles triple products, product+chain rule combinations, and partial derivative product rule. Includes 8 worked practice problems
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
Free stoichiometry calculator with steps. Solve mole ratio, limiting reagent, theoretical yield, percent yield, and gram-to-gram word problems for any balanced chemical equation
Free atomic number calculator. Find protons, neutrons, and electrons for any element or isotope. Includes electron configuration, ion calculator, isotope tool, and mini periodic table with step-by-step working
Free exact mass calculator. Calculate monoisotopic mass from chemical formula, generate MS adduct m/z values [M+H]+, [M+Na]+, view isotope patterns, and compute isotope abundance and average atomic mass with step-by-step working.
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
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
Free buffer pH calculator using the Henderson-Hasselbalch equation. Solve for pH, pKa, or concentration ratio, generate buffer preparation protocols for phosphate, Tris, acetate, citrate & HEPES buffers, and calculate buffer capacity — with step-by-step working
Free Michaelis-Menten calculator — solve for Km, Vmax, velocity, and substrate concentration, generate Lineweaver-Burk plots from data, calculate kcat and catalytic efficiency, and model enzyme inhibition. Full step-by-step working
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