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Chemistry Calculators
Free chemistry calculators to solve molar mass, molarity, stoichiometry, dilutions, pH, limiting reactants, and gas laws. Each tool shows the chemical formulas, constants, and step-by-step steps to help you master chemistry math.
Stoichiometry Calculator
Calculate chemical reaction yields and mole ratios based on balanced equation coefficients.
Balancing Equations Calculator
Balance a chemical equation by finding the smallest set of integer coefficients that conserves every element. Includes a per-element atom-count check on both sides.
Molarity Calculator
Find molarity, moles, volume, or mass from any three known values using M = n / V (and n = m / M when molar mass is supplied). Educational chemistry only, not lab or dosing advice.
Dilution Calculator
Solve M1V1 = M2V2 for any of the four variables, find the dilution factor, and plan simple serial dilutions. Supports mL and L. Educational chemistry only, not lab or dosing advice.
Percent Yield Calculator
Calculate percent yield, actual yield, or theoretical yield using % yield = actual / theoretical x 100. Supports grams, kilograms, milligrams, and moles. Educational chemistry only.
pH Calculator
Convert between pH, pOH, hydrogen ion concentration, and hydroxide ion concentration using pH = -log10[H+] and pH + pOH = 14 (at 25 C). Educational chemistry only.
Grams to Moles Calculator
Convert grams to moles, moles to grams, or solve for molar mass using n = m / M. Manual molar mass input plus common compound presets like H2O, CO2, NaCl, O2, HCl, and glucose.
Ideal Gas Law Calculator
Solve PV = nRT for pressure, volume, moles, or temperature. Supports common units: atm, kPa, Pa, mmHg, psi; L, mL, m3; K, C, F. Assumes ideal gas behavior.
Combined Gas Law Calculator
Solve the combined gas law equation (P1·V1)/T1 = (P2·V2)/T2 for pressure, volume, or temperature.
Molality Calculator
Solve molality (mol/kg) = moles of solute / kg of solvent for any of the three variables, with an optional grams-to-moles helper. Includes a clear molality vs molarity reminder.
Limiting Reactant Calculator
Compare two reactants against the balanced coefficients of a chemical equation. Returns the limiting reactant, the excess reactant, the theoretical product amount, and the leftover excess.
Molecular Weight Calculator
Calculate molar mass (molecular weight) in g/mol from a chemical formula. Supports nested parentheses and groups like H2O, CO2, NaCl, C6H12O6, Ca(OH)2, and K3[Fe(CN)6].
Net Ionic Equation Calculator
Convert standard molecular chemical equations into total ionic and net ionic equations. Enter reactants and products, select phases, and watch spectator ions cancel out.
How to use these chemistry calculators
Our chemistry calculators are designed to be intuitive and educational. Simply select the calculator that corresponds to your problem—such as finding the molarity of a solution or the limiting reactant of a chemical reaction. Input your known values (such as mass in grams, volume in liters, or stoichiometric coefficients from a balanced equation) and click calculate. The tool will instantly display the primary result, along with a detailed breakdown of the steps, conversion calculations, and relevant formulas.
Each calculator incorporates standard values, constants (like Avogadro's number or the ideal gas constant R), and periodic table atomic weights so you can verify your homework, laboratory calculations, and stoichiometry steps with confidence.
Core chemistry equations explained
Several fundamental formulas govern basic chemical calculations:
- Stoichiometry and Mole Conversions: The mole is the bridge between the microscopic world of atoms and the macroscopic world of grams. The core formula is n = m / M, where n is the number of moles, m is the mass in grams, and M is the molar mass (molecular weight) in g/mol.
- Molarity and Solution Concentrations: Molarity measures the concentration of a solute in a solution, defined as M = n / V, where M is molarity (mol/L), n is moles of solute, and V is solution volume in liters. For dilutions, the relationship is M1V1 = M2V2.
- Gas Laws: For ideal gases, the equation of state is the Ideal Gas Law: PV = nRT, where P is pressure, V is volume, n is moles, T is temperature in Kelvin, and R is the universal gas constant (8.314 J/(mol K) or 0.0821 L atm/(mol K)).
Frequently asked questions
A chemistry calculator is a specialized mathematical utility that helps you solve chemical equations, yield relationships, solution concentration problems, and gas laws. Our calculators show the step-by-step conversions and formulas behind the calculations to help you check your work and understand chemistry concepts.
You can calculate molar mass (molecular weight) by summing the average atomic weights of each atom in a chemical formula. For example, to find the molar mass of water (H2O), you add the atomic weights of two hydrogen atoms (2 × 1.008 g/mol) and one oxygen atom (15.999 g/mol) to get approximately 18.015 g/mol.
Molarity (M) is the concentration of a solute expressed as moles of solute per liter of total solution (mol/L). Molality (m) is the concentration expressed as moles of solute per kilogram of solvent (mol/kg). Molarity depends on the volume of the solution, which can change with temperature and pressure, whereas molality depends only on mass and remains constant under varying conditions.
A stoichiometry calculator calculates the quantitative relationships between reactants and products in a chemical reaction. Using the balanced chemical equation's coefficients and molar masses of the substances, it translates starting quantities of reactants into theoretical yields of products.
The limiting reactant (or limiting reagent) is the reactant in a chemical reaction that is fully consumed first, preventing any further product from forming. The amount of product created is limited by this reactant. The other reactants are called excess reactants because some portions of them remain unreacted.
You can solve chemical dilution problems using the formula M1V1 = M2V2, where M1 and V1 are the molarity and volume of the initial concentrated stock solution, and M2 and V2 are the molarity and volume of the final diluted solution. By knowing any three of these variables, you can calculate the fourth.
Last reviewed: June 2026.