How to use this calculator
- Select the gas law that matches the constant conditions.
- Select the unknown variable.
- Enter the known state values and select the units.
- Calculate and review the rearranged relationship.
Formula and variables
Select P1V1=P2V2, V1/T1=V2/T2, P1V1/T1=P2V2/T2, V1/n1=V2/n2, or P1/T1=P2/T2
| Symbol | Meaning | Unit |
|---|---|---|
| 1, 2 | state-one/state-two quantities | compatible units |
Worked example
Choose Boyle for constant temperature, Charles for constant pressure, or Combined when pressure, volume, and temperature all change.
Interpretation
The selected law determines which quantities are assumed constant and which two-state relationship is valid.
Common mistakes
- Use Kelvin in every temperature ratio.
- Choose a law whose constant-condition assumptions match the scenario.
Frequently asked questions
Which gas law should I use?
Use Boyle for constant temperature, Charles for constant pressure, and Combined when pressure and temperature change.
Does the calculator support Avogadro and Gay-Lussac laws?
Yes. Select the required law from the Gas law field.
Why are temperature ratios calculated in Kelvin?
Gas-law ratios require an absolute temperature scale. Celsius and Fahrenheit are converted to Kelvin.
Can I use scientific notation?
Yes. Enter values such as 6.022e23 or 1.0e-6 in a numeric field.
How should I round the result?
Keep extra digits during the calculation. Round the final result to the precision required by your data.