All chemistry calculators

Find protons, neutrons and electrons from an atom’s atomic number, mass number and charge.

Estimate an isotope’s mass from its proton and neutron counts, with the mass number shown separately.

Calculate an abundance-weighted atomic mass from any list of isotope masses and percentages.

Calculate molecular-orbital bond order from bonding and antibonding electron counts.

Compare Pauling electronegativities and explore the direction and approximate character of a bond.

Convert between mass per volume and moles per volume using the solute’s molar mass.

Calculate molar mass, atom counts and elemental mass contributions from a chemical formula.

Find each element’s contribution to a compound’s total mass from its chemical formula.

Find pKa from an acid dissociation constant or from a buffer’s pH and conjugate-pair concentrations.

Find what fraction of stoichiometric reactant mass ends up in the desired product.

Connect a particle count, moles and sample mass using the exact Avogadro constant.

Convert grams to moles, moles to mass, or determine molar mass from a measured mass and amount.

Find approximate hydrogen-ion concentration from pH or pOH, with an adjustable water ion product.

Calculate moles of solute per kilogram of solvent, using either solute moles or mass.

Calculate solution molarity from solute mass or moles and the final solution volume.

Estimate a gas’s molar mass from its measured mass, volume, pressure, and temperature.

Convert mass, amount of substance and particle count with a known molar mass.

Find relative molecular mass and elemental contributions from a chemical formula.

Find each component’s share of the total amount in a binary mixture, from moles or masses.

Convert moles of atoms to an atom count, or reverse the conversion.

Calculate equivalents per liter from solute mass and equivalent weight, or from molarity and a reaction factor.

Convert mass-based parts per million into molar concentration with an explicit solution-density correction.

Estimate nominal residence time from system volume and flow, or from travel length and mean velocity.

Find how much of a stronger and weaker stock to combine for a target concentration.

Estimate the pH of an acid or base buffer using the concentrations of a conjugate pair.

Calculate the final-to-stock dilution factor and distinguish it from the diluent-to-stock ratio.

Find buffer pH from pKa and composition, or find the conjugate-base-to-acid ratio required for a target pH.

Find mass percentage from component masses, or calculate solute and solvent masses for a target mixture.

Normalize up to fifteen component amounts into percentages and scale every amount by a common factor.

Calculate normality from mass and equivalent weight, or the volume required to neutralize a known quantity of acid or base.

Convert between mass percentage and molarity using solution density and solute molar mass.

Calculate mass/volume, mass/mass, or volume/volume percentage with the denominator made explicit.

Calculate pH, pOH, and ion concentrations from measured ions or an ideal strong or weak acid/base solution.

Estimate the vapor pressure of an ideal binary solution from liquid-phase composition and pure-component vapor pressures.

Plan equal-factor dilution steps and see the concentration, transfer volume, and diluent needed at every stage.

Find the stock aliquot for a target concentration and volume, or predict concentration after dilution.

Find an Arrhenius activation energy from a rate constant and frequency factor, or from measurements at two temperatures.

Convert a theoretical product amount and percentage yield into the amount recovered.

Calculate a rate constant from activation energy and temperature, or predict its change between two temperatures.

Use balanced equation coefficients to convert an amount of one substance into the corresponding amount of another.

Compare recovered product with its theoretical amount and express the recovery as a percentage.

Calculate the maximum product mass from a known limiting reactant and a balanced molar ratio.

Estimate the boiling-point rise caused by a nonvolatile solute in a dilute solution.

Estimate how a dissolved solute lowers the freezing point of a dilute solution.

Combine enthalpy, entropy, and temperature to calculate a Gibbs free-energy change.

Count independent intensive variables for an equilibrium system with known components and phases.

Find a cell’s potential difference from cathode and anode reduction potentials.

Estimate deposited or reacted mass from electrical current, time, and electron stoichiometry.

Compare gas effusion rates from molar masses using Graham’s law.

Estimate osmotic pressure from concentration, temperature, and an effective particle factor.

Calculate the combined number of rings and π-bond equivalents in a conventional neutral organic formula.

Find the mass of an enzyme preparation needed for a target activity concentration and final volume.

Calculate an enzyme’s initial reaction rate or solve for its Michaelis constant from compatible kinetic inputs.

Calculate absorbance or concentration and convert absorbance to percent transmittance.