Online Calculators

Convert between moles, mass, and number of particles using n = m/M and N = n × N_A. Calculate moles from mass and molar mass, find mass from moles and molar mass, determine number of particles from moles, or calculate molar mass from mass and moles. Features mass units (g, kg, mg, lb), amount units (mol, mmol, µmol), particle types (molecules, atoms, ions, formula units), and molar masses for 28+ common substances (H₂O, CO₂, NaCl, etc.). Perfect for chemistry students.

Calculate percent composition of chemical compounds using % = (mass part / mass total) × 100. Calculate from chemical formula (H₂O, CO₂, C₆H₁₂O₆, etc.), from experimental masses, find element mass from total mass and percent, or calculate total mass from element mass and percent. Features atomic masses for 50+ elements and 15 common compound formulas. Perfect for chemistry students.

Convert between moles, particles, and mass using Avogadro's number (6.022 × 10²³ particles/mol). Features conversions: moles ↔ particles, mass ↔ particles. Includes particle types (molecules, atoms, ions, electrons, protons, neutrons, formula units), mass units (g, kg, mg, μg), molar masses for 10+ common substances (H₂O 18.015, CO₂ 44.01, NaCl 58.44, etc.), and Avogadro's constant reference. Perfect for chemistry students.

Calculate empirical formula from percentage composition or mass data. Find simplest whole number ratio of elements, determine molecular formula from molar mass, and analyze element composition. Features 28+ elements with atomic masses, 10+ common compounds (H₂O, CO₂, C₆H₁₂O₆, etc.), rounding options (nearest/floor/ceil), and step-by-step solutions. Perfect for chemistry students.

Calculate molecular formula from empirical formula and molar mass using MF = (EF) × n. Enter empirical formula (CH₂O, HO, CH, etc.) and molar mass to find the actual number of atoms in a molecule. Features 10+ common compounds (Glucose: C₆H₁₂O₆, Benzene: C₆H₆, Water: H₂O, etc.) and step-by-step solutions. Perfect for chemistry students.

Calculate hydrate formula (anhydrous·nH₂O) by finding water molecules in a hydrated compound. Input via masses (anhydrous & hydrate mass) or water percentage. Features 8+ common hydrates (CuSO₄·5H₂O, Na₂CO₃·10H₂O, MgSO₄·7H₂O, etc.) with step-by-step solutions. Perfect for chemistry students.

Calculate elemental composition (mass percentage) of each element in a compound using % Element = (Mass of Element / Total Mass) × 100%. Enter chemical formula (H₂O, C₆H₁₂O₆, H₂SO₄, etc.) to find percentage composition, molar mass, and element breakdown. Formula: Mass of Element = Atomic Mass × Number of Atoms. Features 15+ common compounds with step-by-step solutions. Perfect for chemistry students.

Calculate mass percent (percentage composition) of each element in a chemical compound using % Mass = (Mass of Element / Total Mass) × 100%. Enter formula (H₂O, C₆H₁₂O₆, H₂SO₄, etc.) to find percent composition, molar mass, and element breakdown. Formula: Mass of Element = Atomic Mass × Number of Atoms. Perfect for chemistry students.

Calculate stoichiometry for chemical reactions using mole ratios from balanced equations. Find theoretical yield, percent yield, and mass/mole conversions. Uses core formulas: n = m/M, mole ratio = coefficient_P / coefficient_G. Features common reactions (combustion of methane, photosynthesis, Haber process, etc.) and step-by-step solutions. Perfect for chemistry students.

Calculate limiting reagent in chemical reactions to determine which reactant runs out first. Enter balanced equation (CH₄ + 2O₂ → CO₂ + 2H₂O) and reactant amounts (mass or moles) to find limiting reagent, excess reagent, and product formed. Uses formula: Limiting Reagent = smallest (moles / coefficient). Features common reactions (combustion, Haber process, rust formation, etc.) and step-by-step solutions. Perfect for chemistry students.

Calculate excess reagent (leftover reactant) in chemical reactions. Enter balanced equation and reactant amounts (mass or moles) to find limiting reagent, excess reagent quantity (grams and moles), and product formed. Features common reactions (combustion, Haber process, photosynthesis, etc.) and step-by-step solutions. Perfect for chemistry students.

Calculate percent yield to measure chemical reaction efficiency using % Yield = (Actual Yield / Theoretical Yield) × 100%. Enter directly (theoretical & actual yield) or from balanced equation (reactant mass → theoretical yield → percent yield). Features common reactions (combustion, photosynthesis, Haber process) and efficiency analysis. Perfect for chemistry students.

Calculate actual yield from theoretical yield and percent yield using Actual Yield = (Percent Yield / 100) × Theoretical Yield. Enter directly or from balanced chemical equation (reactant mass → theoretical yield → actual yield). Features common reactions (combustion, photosynthesis, Haber process) and efficiency analysis. Perfect for chemistry students.

Calculate theoretical yield (maximum product) from a chemical reaction using stoichiometry. Enter balanced equation, given compound mass, and target product to find theoretical yield in grams and moles. Uses formula: Theoretical Yield = (Given Mass / Molar Mass_G) × (Coeff_P / Coeff_G) × Molar Mass_P. Features common reactions (combustion, photosynthesis, Haber process) and step-by-step solutions. Perfect for chemistry students.

Determine empirical formula from combustion analysis data using mass of CO₂ and H₂O produced. Calculate carbon mass from CO₂, hydrogen mass from H₂O, and oxygen mass by difference. Enter sample mass, CO₂ mass, H₂O mass, and optional molar mass to find molecular formula. Perfect for organic chemistry students.

Calculate molarity (concentration), moles, volume, or mass of solutions using M = n/V and n = m/M. Enter compound formula (NaCl, H₂SO₄, C₆H₁₂O₆) and known values to find missing parameters. Features common compounds, volume unit conversion (L/mL), molar mass calculation, and step-by-step solutions. Perfect for chemistry students.

Calculate normality (N), equivalents, volume, or mass of solutions using N = eq/V and eq = mass/(M/n). Enter compound formula (HCl, H₂SO₄, NaOH), compound type (acid/base/salt/redox), and known values to find missing parameters. Features n-factor calculation, equivalent weight, common compounds, volume conversion (L/mL), and step-by-step solutions. Perfect for chemistry students.

Convert between concentration units (Molarity, mmol/L, μM, g/L, mg/L, % w/v, ppm, ppb, Normality, Molality) and calculate mass from molarity. Features unit conversion, mass calculation from concentration, complex formula support (Ca(OH)₂, Al₂(SO₄)₃), and step-by-step solutions. Perfect for chemistry students.

Calculate mole fraction of each component in a mixture using Xi = ni / ntotal. Enter moles directly or convert from mass with molar mass. Supports complex formulas (Ca(OH)₂, Al₂(SO₄)₃), hydrates (CuSO₄·5H₂O), and multiple components. Features step-by-step solutions and percentage conversion. Perfect for chemistry students.

Calculate mass percentage of each component in a mixture using % = (massᵢ / total mass) × 100%. Enter masses or percentages, supports multiple components, and includes step-by-step solutions. Perfect for chemistry students.

Calculate volume percentage of each component in a mixture using % v/v = (volumeᵢ / total volume) × 100%. Enter volumes or percentages, supports multiple components and units (mL, L, μL, m³), includes step-by-step solutions. Perfect for chemistry students.

Calculate PPM, PPB, and PPT concentrations. Convert between mass/mass, mass/volume, volume/volume, and molarity to ppm. Features 4 conversion types, multiple units (mg/L, μg/L, mL/L), and step-by-step solutions. Perfect for chemistry and environmental science students.

Calculate dilution volumes and concentrations using C₁V₁ = C₂V₂. Find final volume (V₂), final concentration (C₂), stock volume needed (V₁), or perform stock dilution calculations. Supports concentration units (M, mM, μM, nM, pM) and volume units (L, mL, μL, nL). Perfect for chemistry students.

Calculate serial dilution concentrations using Cₙ = C₀ / DFⁿ. Find final concentration, dilution factor, number of steps, or initial concentration. Supports concentration units (M, mM, μM, nM, pM) and stepwise dilution tables. Perfect for laboratory and biology students.

Calculate final concentration when mixing solutions using C₁V₁ + C₂V₂ = C_final × V_final. Mix two solutions, find dilution concentration, or calculate volume needed. Supports molarity (M, mM, μM, nM, pM) and mass concentration (g/L, mg/L, %, w/v). Perfect for chemistry and biology students.

Calculate dilution factor using DF = V_final / V_stock = C_initial / C_final. Calculate from volumes (stock & final volume), serial dilutions (cumulative factor), or concentrations (initial & final). Supports volume units (L, mL, μL, nL) and molarity units (M, mM, μM, nM, pM). Perfect for laboratory and biology students.

Calculate mixing ratios, volumes, and final concentrations for two solutions using the alligation method: A:B = (C_target - C_B) : (C_A - C_target). Find mixing ratio, calculate volume of each solution needed, or determine final concentration when mixing. Supports molarity (M, mM, μM, nM, pM) and mass concentration (g/L, mg/L, %, w/v). Perfect for chemistry and biology students.

Calculate water needed to dilute spirits and alcohol using C₁V₁ = C₂V₂. Find water to add, initial volume needed, or final ABV. Supports multiple units (L, mL, gal, qt, pt, fl oz) and common spirit strengths (vodka 40%, whiskey 40%, everclear 95%, wine 12%, beer 5%). Perfect for home distillers, bartenders, and beverage industry professionals.

Calculate pH, pOH, [H₃O⁺], and [OH⁻] with temperature compensation. Enter concentration values or pH/pOH directly. Features temperature-dependent Kw values (0°C to 100°C), acid/base classification, common substance references (stomach acid pH 1.5, blood pH 7.4, etc.), and step-by-step solutions. Perfect for chemistry students.

Calculate buffer pH using the Henderson-Hasselbalch equation: pH = pKa + log([base]/[acid]). Find pH, base/acid ratio, individual concentrations, or pKa. Features 12 common buffer systems (Acetate, Phosphate, Tris, Carbonate, etc.), concentration units (M, mM, μM, nM, pM), and buffer capacity evaluation. Perfect for chemistry and biology students.

Calculate pH at any point during acid-base titration. Supports strong acid-strong base, weak acid-strong base, and weak base-strong acid titrations. Calculate equivalence point volume, initial pH, half-equivalence pH, and pH at any titrant volume. Features titration curve table and step-by-step solutions. Perfect for chemistry students.

Calculate pKa, Ka, pKb, and Kb for weak acids and bases. Supports 4 methods: from Ka/Kb directly, from pH and concentration, from percent ionization, and from conjugate pKb/pKa. Features acid/base strength analysis and step-by-step solutions. Perfect for chemistry students.

Calculate buffer pH using Henderson-Hasselbalch equation: pH = pKa + log([base]/[acid]). Find pH from pKa and concentrations, calculate base/acid ratio from desired pH, determine individual concentrations from total buffer concentration, or calculate pKa from equilibrium concentrations. Features 8 common buffer systems (Acetate, Phosphate, Tris, Ammonia, etc.) and buffer range assessment. Perfect for chemistry and biology students.

Calculate acid-base neutralization reactions. Find required base volume for complete neutralization or analyze given volumes. Supports monoprotic/diprotic/triprotic acids and monobasic/dibasic/tribasic bases. Calculates moles of H⁺ and OH⁻, limiting reactant, excess reactant, final concentration, and equivalence point. Perfect for chemistry students.

Calculate boiling point elevation using ΔTb = i × Kb × m. Find boiling point elevation (ΔTb), new boiling point, required molality, or ebullioscopic constant (Kb). Features 6 common solvents (water, benzene, chloroform, ethanol, carbon tetrachloride, acetic acid), van't Hoff factors for electrolytes (NaCl, CaCl₂, etc.), and step-by-step solutions. Perfect for chemistry students.

Calculate freezing point depression using ΔTf = i × Kf × m. Find freezing point depression (ΔTf), new freezing point, required molality, or cryoscopic constant (Kf). Features 7 common solvents (water, benzene, chloroform, ethanol, carbon tetrachloride, acetic acid, camphor), van't Hoff factors for electrolytes (NaCl, CaCl₂, etc.), and step-by-step solutions. Perfect for chemistry students.

Calculate osmotic pressure using Π = i × C × R × T. Find osmotic pressure (Π), concentration (C), temperature (T), or molar mass. Supports pressure units (Pa, kPa, atm, bar, psi, mmHg), concentration units (mol/m³, mol/L, mmol/L, μmol/L), temperature units (K, °C, °F), and van't Hoff factors for electrolytes (NaCl, CaCl₂, etc.). Perfect for chemistry and biology students.

Calculate vapor pressure lowering using Raoult's Law: P_solution = χ_solvent × P°_solvent. Find solution vapor pressure, mole fraction of solute, vapor pressure lowering (ΔP), or pure solvent vapor pressure. Supports pressure units (Pa, kPa, atm, bar, psi, mmHg, torr) and van't Hoff factors for electrolytes. Perfect for chemistry students.

Calculate heat transfer using q = m × c × ΔT. Find enthalpy change (ΔH), heat (q), mass, specific heat capacity, or temperature change. Features energy units (J, kJ, cal, kcal), mass units (g, kg), specific heat units (J/g°C, cal/g°C, kJ/kg°C), common substances (water, aluminum, copper, etc.), and step-by-step solutions. Perfect for chemistry and physics students.

Calculate Gibbs free energy using ΔG = ΔH - TΔS. Find ΔG, ΔH, ΔS, temperature (T), or equilibrium constant (K). Features energy units (J, kJ, cal, kcal), entropy units (J/K, kJ/K, cal/K, kcal/K), temperature units (K, °C), spontaneity prediction (spontaneous/non-spontaneous/equilibrium), and common thermodynamic examples (water freezing/boiling, methane combustion). Perfect for chemistry students.

Calculate entropy change (ΔS) for thermodynamic processes. Calculate for isothermal processes (ΔS = Q_rev/T), phase changes (melting/vaporization), temperature changes (heating/cooling), gas expansion/compression, mixing of ideal gases, and chemical reactions using standard molar entropies. Features standard entropy values for 15+ substances, spontaneity prediction, and step-by-step solutions. Perfect for chemistry and physics students.

Calculate heat capacity (C = q/ΔT), specific heat (c = q/(mΔT)), heat transfer (q = mcΔT), mass, or temperature change. Features energy units (J, kJ, cal, kcal), mass units (g, kg), temperature units (K, °C), specific heat units (J/g°C, cal/g°C, J/(mol·K), etc.), common substances (water, aluminum, copper, etc.), and molar heat capacity calculation. Perfect for chemistry and physics students.

Calculate enthalpy change (ΔH) using Hess's Law. Step-by-step method: combine reactions with reversal and multiplication. Formation enthalpies: ΔH°_rxn = Σ ΔH°_f(products) - Σ ΔH°_f(reactants) with 30+ standard values. Combustion enthalpies: scale combustion ΔH by coefficient. Bond energy method: ΔH = Σ BE(broken) - Σ BE(formed) with 25+ bond energies. Perfect for chemistry students.

periodic table with detailed element information. Search by name, symbol, or atomic number. Filter by category (nonmetal, noble gas, alkali metal, transition metal, etc.). View element properties including atomic mass, electron configuration, electronegativity, melting point, boiling point, density, atomic radius, ionization energy, and discovery year. Features grid and list view modes with dark mode support.

Calculate absorbance, concentration, pathlength, or molar absorptivity using A = εcl. Features concentration units (M, mM, μM, nM, pM), pathlength units (cm, mm, m), wavelength units (nm, μm, mm), common compounds (NADH ε=6220 at 340nm, BSA ε=43800 at 280nm, Chlorophyll a ε=84000 at 665nm, etc.), DNA/RNA concentration estimation (dsDNA: 50 μg/mL = 1 AU), transmittance calculation (T = 10⁻ᴬ), and Beer-Lambert linearity check (A ≤ 2.0). Perfect for analytical chemistry, biochemistry, and spectroscopy students.

Calculate cell potential under non-standard conditions using E = E° - (RT/nF) ln Q. Find cell potential (E), reaction quotient (Q), temperature (T), or number of electrons (n). Features 20+ common half-reactions (Li⁺/Li -3.04V to F₂/F⁻ 2.87V), common electrochemical cells (Daniell Cell 1.10V, Zn-Ag 1.56V, etc.), temperature units (K, °C), potential units (V, mV), and step-by-step solutions. Perfect for electrochemistry students.