Science

Ideal gas law calculator

Solve PV = nRT for pressure, volume, amount or temperature.

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ℹ️ PV = nRT with R = 8.314 (kPa·L·mol⁻¹·K⁻¹). Temperature must be in kelvin (K = °C + 273.15). 100% local.

Solve PV = nRT

Choose the unknown to compute, fill in the other values: the tool isolates and computes the variable.

Example (STP)

InputValue
n1 mol
T273.15 K
V22.414 L
Computed P≈ 101.3 kPa

R = 8.314. 100% local calculation.

Frequently asked questions

Which value of R?

R = 8.314, here in kPa·L·mol⁻¹·K⁻¹ (consistent with P in kPa, V in L, T in K).

Why kelvin?

Temperature must be absolute: K = °C + 273.15. Otherwise results are wrong.

What is n?

The amount of substance in moles. You can also solve the equation for n.