Free Chemistry Calculators
A complete suite of 12 free online chemistry calculators for high school and college students. Solve problems for molarity, dilution, pH, stoichiometry, gas laws, half-life and more — instantly, with step-by-step solutions.
Concentration & Solution Calculators
Calculate solution properties used in stoichiometry, lab dilutions, and acid-base chemistry.
Molarity Calculator
Find molarity, moles, or solution volume using M = moles ÷ liters.
Open calculatorDilution Calculator
Solve dilution problems with the M₁V₁ = M₂V₂ formula.
Open calculatorpH and pOH Calculator
Convert between pH, pOH, [H⁺], and [OH⁻] for acid-base problems.
Open calculatorDensity Calculator
Calculate density, mass, or volume using ρ = m ÷ V.
Open calculatorStoichiometry & Reaction Calculators
Tools for working through balanced equations, mole ratios, yields, and limiting reactants.
Stoichiometry Calculator
Convert between moles, grams, and particles using a balanced equation.
Open calculatorEmpirical Formula Calculator
Determine the simplest whole-number ratio of atoms from percent composition.
Open calculatorLimiting Reagent Calculator
Identify the limiting reactant and the maximum product yield.
Open calculatorPercent Yield Calculator
Calculate reaction efficiency with (actual ÷ theoretical) × 100.
Open calculatorGas Law Calculators
Solve problems involving pressure, volume, temperature, and moles of a gas.
Kinetics & Nuclear Chemistry Calculators
Tools for radioactive decay, half-life, and nuclear chemistry problems.
Half-Life Calculator
Find half-life, remaining quantity, or elapsed time for first-order decay.
Open calculatorRadioactive Decay Calculator
Compute remaining isotope amount using N = N₀e⁻ᵏᵗ.
Open calculatorNuclear Decay Calculator
Balance nuclear equations and identify alpha, beta, and gamma decay products.
Open calculatorAbout These Chemistry Calculators
Worksheet Galaxy's chemistry calculator suite is built for students working through general chemistry, AP Chemistry, IB Chemistry, and introductory college courses. Each tool is designed around the formulas and unit conventions used in standard textbooks, so the results align with what your teacher or professor expects.
Every calculator is browser-based, mobile-friendly, and free to use. There is no account required, no paywall, and no ads interrupting the workflow. Calculators run entirely in your browser, so your inputs are never sent to a server.
Who these tools are for
- High school students studying chemistry, AP Chemistry, or IB Chemistry.
- College students in general chemistry, analytical chemistry, or biochemistry.
- Teachers and tutors creating worked examples and answer keys.
- Lab technicians needing quick dilution or molarity checks.
Common formulas at a glance
| Concept | Formula | Variables |
|---|---|---|
| Molarity | M = n ÷ V | n = moles, V = liters |
| Dilution | M₁V₁ = M₂V₂ | initial → final concentration/volume |
| pH | pH = −log[H⁺] | [H⁺] in mol/L |
| Density | ρ = m ÷ V | m = mass, V = volume |
| Ideal Gas Law | PV = nRT | R = 0.0821 L·atm/mol·K |
| Percent Yield | (actual ÷ theoretical) × 100 | yield in grams or moles |
| Half-Life | t½ = 0.693 ÷ k | k = rate constant |
How to Use a Chemistry Calculator
- Pick the right tool. Choose the calculator that matches the variable you need to solve for — molarity, pH, percent yield, etc.
- Enter known values. Each calculator accepts standard SI units (grams, liters, moles, atm, K). Use the unit selector if a different unit is provided.
- Read the worked solution. Each result shows the formula used and how the values were substituted, so you can check your textbook work.
- Verify with a sanity check. Always confirm units match and the answer is the right order of magnitude before submitting.
Frequently Asked Questions
What is the best free online chemistry calculator?
Worksheet Galaxy offers 12 free chemistry calculators covering concentration, gas laws, stoichiometry, kinetics, and nuclear chemistry. All are free, require no sign-up, and provide step-by-step solutions suitable for high school and college students.
How do I calculate molarity?
Molarity is moles of solute divided by liters of solution: M = n ÷ V. For example, dissolving 0.5 mol of NaCl in 2 L of water gives a molarity of 0.25 M. Use the molarity calculator to solve for any variable.
What is the difference between molarity and molality?
Molarity (M) is moles of solute per liter of solution. Molality (m) is moles of solute per kilogram of solvent. Molality is preferred when temperature changes, because it does not depend on volume.
How do you calculate pH from hydrogen ion concentration?
Use pH = −log[H⁺]. For example, [H⁺] = 1 × 10⁻⁴ M gives pH = 4. The pH and pOH calculator handles this and the reverse conversion automatically.
How is half-life calculated in chemistry?
For first-order reactions and radioactive decay, t½ = 0.693 ÷ k, where k is the rate constant. After one half-life 50% remains, after two half-lives 25%, and so on. Try the half-life calculator.
What is percent yield in chemistry?
Percent yield = (actual yield ÷ theoretical yield) × 100. It measures reaction efficiency. A yield below 100% is normal due to side reactions, incomplete reactions, or losses during purification.
Are these chemistry calculators free to use?
Yes. All 12 calculators are 100% free, require no registration, and work on desktop, tablet, and mobile.
Do the calculators show step-by-step solutions?
Yes. Each calculator displays the formula being used and the substituted values, so you can compare each step to your textbook or homework method.