Essential tools for chemical analysis and molecular calculations
Advanced calculators for chemistry professionals, students, and researchers
Our chemistry calculators are designed for students, educators, and professionals in chemistry and related fields. These tools help you perform complex chemical calculations with precision and accuracy, from atomic structure analysis to molecular composition calculations.
Professional-grade calculators for atomic structure, properties, and composition analysis.
Get accurate results for chemical formulas, molecular weights, and composition analysis.
Essential tools for chemical experiments, calculations, and scientific analysis.
Calculate the activation energy of a chemical reaction from temperature, rate coefficient, and frequency factor using the Arrhenius equation. Supports °C, °F, and K temperatures with seven time scales and five energy units.
Calculate the activity coefficient of an ion using the Debye-Hückel limiting law from ion charge, ionic strength, and temperature-dependent constant. Bidirectional solver with molar and millimolar units.
Calculate the actual yield of a chemical reaction from theoretical yield and percent yield. Supports 10 mass units from nanograms to imperial tons with bidirectional solving.
Calculate the air-fuel ratio (AFR) for complete combustion of common fuels. Select a fuel such as methane, propane, or hydrogen to see its stoichiometric AFR, or enter the mass of air and fuel to find the missing value.
Calculate the alligation ratio and required volumes to mix a higher and lower concentration into a target intermediate concentration. Supports any consistent concentration unit and 11 volume units with bidirectional solving.
Solve the Arrhenius equation for rate constant (k), activation energy (Ea), frequency factor (A), or temperature (T). Supports exponential and logarithmic forms with per-mole and per-molecule bases.
Calculate atomic properties including protons, neutrons, electrons, atomic number and mass number
Calculate the atom economy of any chemical reaction from the masses or molecular weights of the reagents and the desired product. See how much of your reactants end up in the product and how much becomes waste.
Calculate atomic mass from protons and neutrons. Get atomic mass in various units including atomic mass units (u), kilograms, and more.
Calculate the average atomic mass of an element based on the isotopes and their natural abundances.
Calculate moles, mass, molecular weight, and number of atoms using Avogadro's number (Nₐ = 6.02214076 × 10²³). Bidirectional stoichiometry calculator with metric and imperial mass units.
Calculate how much bleach and water you need to mix for a desired chlorine concentration. Supports mg/L, ppm, g/L, and 20+ volume units with bidirectional solving.
Find the boiling point of water at any altitude, or solve the altitude and pressure back from a boiling temperature using the standard barometric relation.
Find the boiling point of a liquid at any pressure with the Clausius-Clapeyron relation. Tabulated data for nine substances, twelve pressure scales, three temperature scales, and reverse solves for pressure, temperature or heat of vaporization.
Work out how far a dissolved solute raises a solution past the boiling point of its solvent, with reverse solves for the ebullioscopic constant, the molality or the van't Hoff factor.
Calculate the bond order of a molecule or ion from bonding and antibonding electrons using molecular orbital theory.
Calculate buffer capacity (β) from the amount of acid or base and the change in pH, or solve for any missing variable. Supports 11 volume units for mol-based concentrations.
Calculate the pH of an acid or base buffer solution using the Henderson-Hasselbalch equation. Supports bidirectional solving for Ka/pKa, Kb/pKb, and molar concentrations.
Find the electromotive force of a galvanic cell from its anode and cathode potentials, or pin the cell voltage and one electrode to solve back for the other, in mV, V, kV or MV.
Balance a chemical reaction and get the smallest whole-number coefficients. Supports bracketed groups such as Fe(OH)3, user-supplied coefficients, and unicode subscripts.
Name any ionic compound from its cation and anion, by symbol or by name. See the balanced subscripts and systematic compound name instantly.
Calculate solution concentration in five ways: mass volume percent (w/v%), mass percent (w/w%), molarity, solution dilution, and concentration from density. Supports metric and imperial units with bidirectional solving.
Find the diffusion coefficient from the Einstein-Smoluchowski relation D = k_B·T/ξ, with the Stokes friction coefficient of seven particle geometries, or supply a measured friction coefficient to work back to the particle size.
Calculate the dilution factor from initial volume, dilutant volume, and final volume. Supports 13 metric and imperial volume units with bidirectional solving for total-to-stock and dilutant-to-stock ratios.
Calculate the effective nuclear charge Z_eff of any electron using Slater’s rules. Pick an element and an orbital to see the total shielding and effective charge for all 118 elements.
Find how much mass an electric current deposits on or releases from an electrode, then solve back for the charge, the current, the plating time or the electrochemical constant of the substance.
Get the electron configuration for any element from the periodic table. View atomic number, atomic mass, and valence electrons.
Calculate electronegativity difference between two elements and determine bond type (ionic, polar covalent, or nonpolar covalent).
Calculate the empirical formula of a compound from percent composition or mass data. Enter up to 10 elements with their percentages or masses to find the simplest whole-number ratio.
Solve entropy in three ways: reaction entropy change from product and reactant entropies, the Gibbs free energy change from enthalpy, temperature and entropy, and the isothermal entropy change of an ideal gas from a volume or pressure ratio.
Solve the equilibrium constant Kc of a reversible reaction aA + bB ⇌ cC + dD. Compute K from stoichiometric coefficients and equilibrium molar concentrations, or back-solve any concentration or coefficient. Nine molar scales from M to yM.
Solve the Gibbs free energy equation ΔG = ΔH − T×ΔS in any direction: compute the Gibbs free energy change, the enthalpy change, the entropy change or the absolute temperature from the other three, with joules, kilojoules, calories, kilocalories and °C, °F or K.
Find the degrees of freedom of a heterogeneous system with Gibbs' phase rule F = C − P + f: enter the number of components and phases and choose whether pressure, temperature, both or neither are held constant, or solve backwards for a missing count.
Convert between grams, moles, and molar mass for any chemical substance. Supports 25 common compounds and multiple mass and mole units with bidirectional solving.
Work out how much of a substance is left after a given time, then solve back for the half-life, the elapsed time, the decay constant or the mean lifetime from a measured quantity, across seven time scales from seconds to years.
Convert a fuel's lower heating value into its heat of combustion, and solve back for the lower heating value, the heat of vaporization of water or either mole count. Ten common fuels are tabulated with their heating values and their molar water yields.
Calculate buffer pH, Ka, pKa, or conjugate base and acid concentrations using the Henderson-Hasselbalch equation. Supports molar, millimolar, and micromolar units with bidirectional solving.
Determine the hydrogen ion concentration [H⁺] from pH using this hydrogen ion concentration calculator. Also calculates pOH and supports molar concentration units.
Find the fraction or the percent of an adsorbent surface covered by an adsorbate with the Langmuir isotherm θ = K_eq·P / (1 + K_eq·P). Enter the adsorption equilibrium constant with a partial pressure or a molar concentration, or start from a measured coverage and solve back for K_eq or P, in eight pressure units plus mol/L.
Estimate the lattice energy of an ionic compound from its cation, anion, crystal structure and interatomic distance, comparing the Kapustinskii, Born-Landé, Born-Mayer and hard-sphere models.
Convert mass concentration (g/L, kg/L, mg/L) to molar concentration (M, mM, μM) and vice versa using molar mass.
Calculate the mass percent (w/w%) concentration of a solute in a solution. Bidirectional calculator with 12 mass units and percentage or fraction output.
Calculate the percentage and scaled amount of each substance in a mixture. Supports up to 15 ingredients with a batch multiplier.
Calculate the molal concentration of a solution from moles of solute and mass of the solvent. Converts between mass, molar mass, and moles with metric and imperial units.
Calculate the molar mass of any chemical compound by selecting up to six elements and their quantities.
Calculate the molar mass of a gas using the ideal gas law. Enter pressure, volume, temperature, and mass to find moles and molar mass with bidirectional solving.
Scale a balanced chemical equation to real mole counts and masses. Enter the coefficients and the molar ratio, moles and masses follow for every reactant and product.
Calculate solution molarity from mass, volume, and molecular weight. Converts between molar, millimolar, micromolar, and other concentration units with bidirectional solving.
Convert between mass, molecular weight, moles, and number of molecules for any chemical substance. Bidirectional stoichiometry calculator with 13 mass units, 4 molar mass units, 5 mole units, and 7 scientific notation scales.
Calculate the mole fraction of a solution from solute and solvent moles. Convert between mole fraction, mole percent, and molality with support for multiple mole and mass units.
Calculate the molecular weight of any compound by selecting up to six elements and their atom counts.
Convert between number of moles and number of atoms using Avogadro’s constant. Supports scientific notation and mole sub-units from pmol to mol.
Find the reduction potential a half-cell or full cell really shows from its standard potential, the temperature, the electrons transferred and the activities of the oxidized and reduced forms, using the exact SI gas and Faraday constants.
Reduce a molecular equation to its net ionic form. Balances the reaction, splits soluble compounds into ions, and names the spectator ions that cancel out.
Calculate the normality of a solution from solute weight, solvent volume, and equivalent weight. Supports 14 mass units, 21 volume units, and bidirectional solving for all four parameters.
Calculate the normality (equivalent concentration) of a solution from solute mass, equivalent weight, and volume. Supports microgram, milligram, gram, microliter, milliliter, liter, and US gallon units with bidirectional solving.
Calculate the percent composition of each element in a chemical compound by mass. Select up to five elements, enter their atom counts, and see element masses, molecular weight, and percent composition instantly.
Calculate the percent ionic character of a chemical bond from the electronegativity difference (Pauling’s formula) or from the measured and calculated dipole moments. Pick two elements or enter dipole data to classify a bond as covalent, polar covalent, or ionic.
Calculate percent solution concentration three ways: weight by volume (w/v%), weight percentage (w/w%), and volume percentage (v/v%). Convert to ppm, mass per volume, or custom ratios with bidirectional solving.
Find the percent yield of a chemical reaction from the mass of product you isolated and the mass your balanced equation predicts. Solves for actual yield, theoretical yield or percent yield in eleven mass units from micrograms to imperial tons.
Convert percentage concentration to molarity (mol/L) for any solution. Supports preset substances, custom molar mass, density, and multiple unit systems with bidirectional solving.
Calculate pH from acid or base concentration, from mass and volume, or from hydrogen ion, hydroxide ion, or pOH values with bidirectional solving.
Calculate the pKa of an acid from pH using the Henderson-Hasselbalch equation, or directly from the acid dissociation constant (Ka). Supports molar concentration units from M to yM.
Convert ppm (parts per million) to molarity (mol/L) for any dissolved element or compound. Supports ppm and ppb input, multiple molarity scales, and adjustable solvent density.
Calculate the vapor pressure of an ideal solution using Raoult's Law, mole fraction of solvent, or pure solvent vapor pressure from moles of solute and solvent. Includes vapor pressure chart.
Solve rate laws in either direction for a unimolecular, bimolecular or trimolecular step. Reads the rate constant, total reaction order and reaction rate from reactant orders, molar concentrations and a half life, or back-solves the half life, k or any concentration.
Compare the effusion or diffusion rates of two gases from their molar masses, or work back from a measured rate pair to the molar mass of either gas, in all four directions of Graham's law.
Compute the reaction quotient Q of a reversible reaction at any point in time. Enter up to six reagent and six product pairs with their stoichiometric coefficients and molar activities, or solve backwards for Q, any activity, or any coefficient.
Calculate the reconstitution concentration of a solution from the mass of dry ingredient and volume of diluent. Supports mass, volume, and concentration units with bidirectional solving.
Calculate the saponification value of fats and oils from HCl titration data. Supports 21 volume units, 3 molarity units, and 7 mass units with bidirectional solving.
Plan serial dilutions from a dilution factor or a concentration range. Returns the minimum volume required, the volume to move at each step, the stock and dilutant volumes, the dilution factor of every solution, and the concentration of up to ten solutions.
Calculate how to dilute a stock solution using the C₁V₁ = C₂V₂ equation. Enter any three of initial concentration, initial volume, final concentration, or final volume to find the missing value. Supports 9 molar concentration units and 22 volume units.
Convert a gas volume measured at any temperature and pressure into its volume and its number of moles at standard temperature and pressure (273.15 K and 1 atm), and solve back from an amount of gas to the measured conditions.
Calculate total dissolved solids (TDS) from a water analysis by summing ten anions and ten cations, or from an electrical conductivity reading with a conversion factor. Also returns the anion and cation totals, the mEq/L and mmol/L sums, and the anion-cation balance.
Find the maximum mass of product a balanced reaction can give from its limiting reagent. Solve backwards for the limiting reagent mass, either molecular weight, either amount in moles, either stoichiometry coefficient, or the theoretical yield itself, in 13 mass, 4 molar-mass and 5 mole units.
Calculate acid-base titration parameters including concentration, volume, and ion donation. Supports molarity units from M to yM and various volume units.
Solve the Clausius-Clapeyron equation for vapor pressure, boiling temperature or molar enthalpy of vaporization in either direction, and apply Raoult's law to a solution through the solvent's mole fraction. Supports four temperature scales, twelve pressure units and five per-mole energy scales.
Read the saturation vapor pressure of water from its temperature with five approximations — simplified, Antoine, Magnus, Tetens and Buck — including the over-ice fits below freezing, in twelve pressure units.
Choose a calculator above and start exploring the world of chemistry with precision and accuracy.
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