Chemistry Calculator

Comprehensive collection of chemical calculations for molar mass, concentration, pH value and more

General Chemistry

Molar Mass (M = Σ(m))

Calculate the molar mass from chemical formula. Atomic mass, molecular formulas, H2O, CO2, NaCl and more

pH Value (pH = -log[H⁺])

Calculate pH, pOH and concentration of H⁺ and OH⁻ ions. For acids, bases and neutral solutions

Percentage Composition (% Element)

Calculate mass percentages of elements in compounds. Element %, empirical formula, mass percentage

Complex Formation (Kf = [ML]/([M]·[L]))

Complexometric titrations and Kf calculations. EDTA, metal-ligand equilibria, and complexation degree

Percent Error (% error)

Assess laboratory accuracy and measurement deviation. Percent error, relative error, and target-vs-observed analysis

Calibration Line (Linear Regression) (y = m·x + b)

Build calibration curves with linear regression. Slope, intercept, R², and unknown sample back-calculation

Detection/Quantification Limit (LOD/LOQ) (LOD = 3.3·σ/S)

Calculate detection and quantification limits from signal spread and calibration slope for analytical method validation

Enthalpy/Entropy Unit Conversion (ΔG = ΔH - T·ΔS)

Convert ΔH/ΔS between J, kJ, cal, kcal and validate unit consistency for Gibbs free-energy calculations

Solutions and Concentration

Molar Concentration (c = n/V)

Calculate molar concentration of solutions. Molarity, amount of substance, volume, mol/L

Dilution (c₁V₁=c₂V₂)

Calculate solution dilutions. Dilution law, concentration, volume, serial dilution

Mole Fraction (χ = nᵢ/n_total)

Calculate mole fraction in mixtures. Mole fraction, mole ratio, χ value

Molality (b = n/m)

Calculate solution molality. Moles per kg of solvent, mol/kg

Molar Volume (V = n × Vm)

Calculate gas volume and moles. Molar volume, STP, SATP, ideal gas law

Acid-Base Chemistry

Titration (n = c·V)

Calculate titrations and concentrations. Acid-base titration, equivalence point, concentration and volume

Redox Titrations (n_Ox×e⁻_Ox = n_Red×e⁻_Red)

Calculate redox titrations via electron balance. KMnO₄ and iodine titration workflows with equivalence check

Titration Curves (Polyprotic Systems) (pH, pK_a, V_eq)

Calculate pH regions, buffer zones, and equivalence points for diprotic and triprotic titration systems

Species Distribution vs pH (\(\alpha_i\), pH, pK_a)

Calculate fractions and concentrations of protonated/deprotonated species as a function of pH

Stoichiometry

Stoichiometry (n = m/M)

Calculate moles, mass and ratios in chemical reactions. With molar mass and chemical equations

Buffer and Equilibrium

pKa / Acid Dissociation Constant (pKa = -log Ka)

Calculate pKa and Ka. Acid strength, dissociation constant, buffer range, Henderson-Hasselbalch

Henderson-Hasselbalch (pH = pKa + log)

Calculate pH of buffer solutions. Buffer, acid-base, pKa and salt form/acid form ratio

Buffer Capacity (β = dn/dpH)

Quantify buffer effect. Compute β, required amount and resulting pH change in buffer systems

Buffer Design (Target pH, Mole Planning) (R = 10^pH-pK_a)

Plan acid/base moles for a desired target pH and optionally compute required weigh-in masses

Electrochemistry

Nernst Equation (E = E^° - RT/nF·lnQ)

Compute electrode and cell potentials under non-standard conditions. Concentration cell, temperature and Q effects

Cell Voltage (Non-Standard) (E_cell = E^° - RT/nF·lnQ)

Context-focused page for real operating cell voltage with overall-reaction and half-cell Nernst models

Faraday Electrolysis (m = M·I·t/(zF))

Compute deposited mass, amount, and current demand using Faraday's electrolysis laws

Thermodynamics

Solubility Product (Ksp) (Ksp = [A]^a×[B]^b)

Calculate Ksp and precipitation prediction. Solubility, ion product Q, precipitation

Henry's Law (c = k_H × P)

Calculate gas concentration in solution. CO₂, O₂, Henry constant, partial pressure

Partial Pressures (P_i = χ_i × P_total)

Calculate component pressure by Dalton's law. Gas mixtures, mole fraction χ, total pressure and partial pressure

Arrhenius Equation (k = A·e^-Ea/RT)

Calculate rate constant, activation energy and temperature effect. Kinetics, Ea, k(T)

Van’t Hoff (Temperature Dependence of K) (ln(K₂/K₁) = -ΔH°/R·Δ(1/T))

Compute temperature dependence of equilibrium constant K. Solve K₂ from K₁, estimate ΔH°, and determine target temperature with Van’t Hoff

Reaction Order / Half-Life (t_1/2, n, k)

Compute half-life and concentration profiles for 0th, 1st, and 2nd order kinetics. Kinetic evaluation using n, k, and c(t)

Rate Constant (k) (k, c(t), t)

Compute k, c(t), and half-life relations for 0th, 1st, and 2nd order kinetics with symbol legend

Osmotic Pressure (π = i·c·R·T)

Calculate osmotic pressure of solutions. van't Hoff equation, colligative properties, osmosis

Colligative Properties (ΔT = K × m)

Calculate freezing point depression and boiling point elevation. ΔTf, ΔTb, molality and solution effects

Ionic Strength (I = 0.5×Σ(cᵢ×zᵢ²))

Calculate ionic strength, activity coefficient and Debye-Hückel behavior. Electrolytes, γ and real-solution effects

Activity Coefficient (γ) (log γ = -0.5·z²·√I)

Debye-Hückel calculator with detailed examples. γ from I and z, inverse computation, and monovalent/divalent comparison

Ionic Mobility / Conductivity (κ = F·1000·c·Σ(ν|z|u))

Compute conductivity from ionic mobilities, back-calculate mobility, and analyze cation/anion contribution shares with detailed examples

Raoult + Activity Combined (P = x·γ·P°)

Combined calculator for Raoult’s law with activity correction. Partial pressure, γ back-calculation, and binary total pressure with detailed practical examples

Vapor Pressure (ln P₂/P₁ = -ΔH/R·Δ(1/T))

Calculate vapor pressure with Clausius-Clapeyron. Enthalpy of vaporization, temperature dependence, boiling point

Clausius-Clapeyron Equation (ln(P₂/P₁) = -ΔH_vap/R·Δ(1/T))

Compute vapor-pressure temperature relations, enthalpy of vaporization, and target temperatures with detailed Clausius-Clapeyron examples

Gibbs Free Energy (ΔG = ΔH - T·ΔS)

Calculate Gibbs Free Energy and spontaneity. Enthalpy, entropy, equilibrium constant, thermodynamics

About This Collection

This collection provides professional calculators for the most important chemical calculations in everyday laboratory work, research and education. All calculators use international standards and common chemistry conventions.

The calculators support you with:

Precise molar calculations
Concentration conversion and dilutions
pH value and pOH calculations
Stoichiometric analysis
Buffer capacity and equilibrium calculations

Quick Reference

M = Σ(m)

Molar Mass

c = n/V

Concentration

pH = -log[H⁺]

pH Value

ΔG = ΔH - TΔS

Gibbs Energy

c₁V₁ = c₂V₂

Dilution