Combined Gas Law Calculator
Heating 2 L of gas from 20 °C to 100 °C while doubling the pressure leaves a final volume of 1.2729 L, from P₁V₁/T₁ = P₂V₂/T₂.
1.27289783387344 L
Full answer, then cut to fewer decimals (not rounded):
- 1.27289783387344 L
- 1.2728978338734 L
- 1.272897833873 L
- 1.27289783387 L
- 1.2728978338 L
- 1.272897833 L
- 1.27289783 L
- 1.2728978 L
- 1.272897 L
- 1.27289 L
- 1.2728 L
- 1.272 L
- 1.27 L
- 1.2 L
- In mL
- 1272.897834 mL
- In m³
- 0.001272897834 m³
- In ft³
- 0.04495196277 ft³
- In gal (US)
- 0.3362640332 gal (US)
- Special cases
- Boyle (T constant): P₁V₁ = P₂V₂ · Charles (P constant): V₁/T₁ = V₂/T₂ · Gay-Lussac (V constant): P₁/T₁ = P₂/T₂
Step-by-step solution
- V₂ = P₁ × V₁ × T₂ ÷ (T₁ × P₂)
- V₂ = 1 × 2 × 373.15 ÷ (293.15 × 2)
- V₂ = 1.272897834 L
Combined Gas Law Formula
P₁V₁ / T₁ = P₂V₂ / T₂
P pressure, V volume, T absolute temperature (K) for a fixed amount of gas
Worked Example
2 L of gas at 1 atm and 20 °C heated to 100 °C while the pressure doubles to 2 atm:
- V₂ = P₁ × V₁ × T₂ ÷ (T₁ × P₂)
- V₂ = 1 × 2 × 373.15 ÷ (293.15 × 2)
- V₂ = 1.272897834 L
In m³: 0.001272897834 m³ · In ft³: 0.04495196277 ft³ · In gal (US): 0.3362640332 gal (US) · Special cases: Boyle (T constant): P₁V₁ = P₂V₂ · Charles (P constant): V₁/T₁ = V₂/T₂ · Gay-Lussac (V constant): P₁/T₁ = P₂/T₂
Pressure units must match only each other
Because the law is a ratio, P₁ and P₂ may be in any unit as long as you read the answer in the same one. The calculator converts each to atmospheres internally, so mixing kPa and psi is safe too.
More Heat and Gases Calculators
-
Specific Heat Calculator
Q = m c ΔT
Q heat (J), m mass (kg), c specific heat capacity (J/(kg·K)), ΔT temperature change (K or °C)
Example: Heating 1 kg of water by 10 °C: Heat energy Q = 41840 J.
Frequently asked questions
Why must temperature be in kelvin?
The law uses absolute temperature. 20 °C is 293.15 K; using Celsius directly would give wrong or infinite answers near 0 °C. Pick °C or °F and the calculator converts.
How do I use it for Boyle’s or Charles’s law?
Keep the constant quantity equal on both sides: same T for Boyle (P₁V₁ = P₂V₂), same P for Charles (V₁/T₁ = V₂/T₂).
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures .
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Combined Gas Law Calculator. Retrieved October 25, 2026, from https://scientificconverters.com/calculators/combined-gas-law-calculator/
IEEE
Scientific Converters, "Combined Gas Law Calculator," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/calculators/combined-gas-law-calculator/