Chemistry & Science Calculator
Molar mass, solution concentration, dilution, gas laws, pH analysis, and a full scientific unit converter — everything a student or lab needs.
Select units and enter a value to convert
Type a chemical formula above — results appear instantly
Enter solute mass, volume, and molar mass to see all concentration units
Leave one field empty — it will be solved using C₁V₁ = C₂V₂
Fill in three of the four variables (P, V, n, T) to solve for the fourth
Select a mode, fill in values, and click Calculate pH
Advanced Unit Converter
Physics and chemistry units with automatic dimension validation. Prevents invalid conversions like kg → Kelvin.
Molar Mass Calculator
Parse any chemical formula including nested parentheses: Fe₂(SO₄)₃, Ca(OH)₂, complex organics.
Concentration Calculator
From mass and volume to Molarity, Molality, Normality, % w/v, % w/w, ppm — all at once.
Dilution Calculator
C₁V₁ = C₂V₂ — solve for any unknown. Includes step-by-step instructions.
Gas Law PV=nRT
Solve for P, V, n, or T with unit conversion built in. Supports atm, Pa, kPa, bar, torr.
pH Analyzer
Strong/weak acid and base pH, Henderson–Hasselbalch for buffers, Ka/Kb equilibria.
About the Chemistry Calculator Suite
This free online tool covers the most common calculations in general chemistry, analytical chemistry, and biochemistry lab courses. All calculations are performed in your browser — no data is sent to any server.
Molar Mass
Enter any chemical formula in standard notation. Nested parentheses (e.g. Fe2(SO4)3), polyatomic ions, and hydrates are all supported. The tool parses the formula into elements and multiplies each element's atomic mass by its count, then sums them.
Solution Concentration
Provide the solute mass (g), solution volume (mL), and molar mass (g/mol) to instantly obtain Molarity (mol/L), Molality (mol/kg), Normality (eq/L), mass percent (% w/w), volume percent (% w/v), and parts per million (ppm mg/L).
Dilution C₁V₁ = C₂V₂
The dilution equation states that the moles of solute are conserved. Enter any three of the four variables and the fourth is solved automatically. The results include step-by-step lab instructions.
Gas Laws PV = nRT
The ideal gas law relates pressure (P), volume (V), moles (n) and temperature (T) via the gas constant R = 0.08206 L·atm/mol·K. The calculator accepts multiple pressure and temperature units and converts internally.
pH Calculation
For strong acids, pH = −log[H⁺]. For weak acids, the tool solves the equilibrium Ka = x²/(C−x) for [H⁺]. Buffer pH is calculated using the Henderson–Hasselbalch equation: pH = pKa + log([A⁻]/[HA]).
Free Online Unit Converter
Convert between units instantly: length, weight, temperature, volume, area, speed, time, pressure, energy and data. Type a value, pick your units and see the result update in real time. It is handy for cooking, travel, school, engineering and everyday questions.
Metric and imperial units sit side by side, so you can go from kilometres to miles, kilograms to pounds, or Celsius to Fahrenheit without doing the maths yourself.
100+ units in 10 categories
From millimetres to miles, grams to tons and bits to terabytes.
Instant results
The answer updates as you type, with no button to press.
Metric and imperial
Switch between systems with one selection.
Accurate
Uses standard conversion factors for reliable results.
How to use it
- Choose a category such as length or weight.
- Enter the value you want to convert.
- Select the from and to units.
- Read the converted value instantly.
Frequently asked questions
How do I convert kilometres to miles?
Multiply kilometres by 0.621371. For example, 10 km is about 6.21 miles.
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. For example, 20 C is 68 F.
Is the unit converter free?
Yes. It is free to use with no signup.
How accurate are the conversions?
They use standard, internationally accepted conversion factors.