Combined Gas Calculator
Last updated: June 2026 · Free · No sign-up required
Enter values above and click Calculate to see your result instantly.
What the Combined Gas Calculator does
Under the hood, this calculator applies P₂ = P₁ × V₁ × T₂ ÷ (T₁ × V₂), temperatures in kelvin, so the combined gas law calculator result you see is genuine math, not a lookup table.
If you are new to combined gas law calculator, start with the worked example in the methodology section below — it walks the formula end-to-end with real numbers — then use the quick-reference table for common scenarios.
Quick reference
| Held constant | Law | Relationship |
|---|---|---|
| Temperature | Boyle | P₁V₁ = P₂V₂ |
| Pressure | Charles | V₁÷T₁ = V₂÷T₂ |
| Volume | Gay-Lussac | P₁÷T₁ = P₂÷T₂ |
| Nothing | Combined | P₁V₁÷T₁ = P₂V₂÷T₂ |
functions Shows the working, not just the answer
For students and teachers, the final number is only half the value. Every math tool here exposes the formula it applied, the intermediate steps, and the rounding rule, so you can follow along, check your homework, or use the answer in a proof or report with confidence.
calculate Accurate to the spec
Calculations use 64-bit floating point with sensible rounding for the domain (currency to 2 decimals, percentages to 4 decimals, algebra to 6 significant figures). Where exact rational arithmetic matters — fractions, factorials, simplification — we use a dedicated BigNumber path so 1/3 + 1/6 returns ½, not 0.49999.
school Free for classroom use
Educators are welcome to link to any math calculator on CalcaTools from a class site, Google Classroom, or worksheet. The pages are mobile-friendly, free, ad-supported (so we can keep them free) and have no sign-up wall — students just click and use them in class or at home.
tips_and_updates Pair with the spoke articles
Below the calculator we link a small set of plain-English explainer pages — "What is a percentage?", "Why does PEMDAS matter?", and so on. They cover the underlying concept in 4–6 short paragraphs. Read those before the calculator if the topic is new, or after if you want the extra context.
Interpretation guide
| Change | Effect on P₂ |
|---|---|
| Volume halved | Pressure doubles (T fixed) |
| Temperature up | Pressure rises (V fixed) |
| Both V↓ and T↑ | Effects multiply |
Formula & methodology
Formula: P₂ = P₁ × V₁ × T₂ ÷ (T₁ × V₂), temperatures in kelvin
- Enter the initial pressure, volume and temperature (kelvin: °C + 273.15).
- Enter the final volume and temperature.
- The tool rearranges P₁V₁÷T₁ = P₂V₂÷T₂ to P₂ = P₁V₁T₂÷(T₁V₂) and verifies both sides match.
Example: P₁ = 1 atm, V₁ = 2 L, T₁ = 300 K, compressed to 1 L at 350 K → P₂ = 2.333 atm.