What this calculator does
STP conversion works out corrects a measured gas volume to STP and finds the equivalent moles. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaV(STP) = V × (273.15/T) × (P/P0); n = V(STP)/22.414 L (IUPAC STP: 0 °C, 100 kPa) or /22.711 L (old STP: 0 °C, 101.325 kPa)
The inputs explained
| Field | What to enter |
|---|---|
| Measured volume (L) | A number, measured in L. Starts at 5. |
| Measured temperature (°C) | A number, measured in °C. Starts at 25. |
| Measured pressure (kPa) | A number, measured in kPa. Starts at 101.325. |
| STP convention | Choose from IUPAC (0 °C, 100 kPa, Vm=22.711 L/mol), Traditional (0 °C, 101.325 kPa, Vm=22.414 L/mol). |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with measured volume
Every other input is held at the calculator’s starting values while measured volume varies. Select any row to load that scenario into the calculator.