How to use the combined gas law calculator
Find the final pressure of a gas when volume and temperature change. Enter initial pressure, initial volume, initial temperature, final volume, final temperature in the fields above; the final pressure is computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- P1 — Initial pressure (kPa)
- V1 — Initial volume (L)
- T1 — Initial temperature (K)
- V2 — Final volume (L)
- T2 — Final temperature (K)
Worked example
With initial pressure = 101.3 kPa, initial volume = 10 L, initial temperature = 300 K, final volume = 6 L, final temperature = 350 K, the calculator gives final pressure ≈ 196.9722 kPa.
Frequently asked questions
What is the formula for the combined gas law calculation?
Final pressure (kPa) = P1 × V1 × T2 / (T1 × V2). Here P1 is initial pressure (kPa), V1 is initial volume (L), T1 is initial temperature (K), V2 is final volume (L), T2 is final temperature (K).
What inputs do I need for the combined gas law calculator?
You need initial pressure in kPa, initial volume in L, initial temperature in K, final volume in L, final temperature in K. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.