Thermodynamics & Gas Law Calculators

Ideal Gas Law

P · V = n · R · T

Pressure, volume, temperature, moles, and density of an ideal gas — solve any variable.

Calculate

Specific Gas Constant

R_specific = R / M

Specific gas constant from universal R and molar mass for a given gas.

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Temperature Conversion

°F = (9/5)·°C + 32

Convert between Celsius, Fahrenheit, Kelvin, and Rankine.

Convert

Thermal Conductivity

q = k · A · ΔT / L

Conductive heat transfer rate through a slab from conductivity, area, and temperature gradient.

Calculate

Thermal Diffusivity

α = k / (ρ · cp)

Thermal diffusivity from conductivity, density, and specific heat.

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Thermal Expansion

ΔL = α · L · ΔT

Linear and volumetric thermal expansion from coefficient and temperature change.

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Dry Adiabatic Lapse Rate

Γ = g / cp ≈ 9.8 °C/km

Temperature change with altitude for a rising parcel of dry, unsaturated air.

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Heat Index

HI (Rothfusz regression)

Apparent temperature combining ambient temperature and relative humidity.

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Wind Chill Temperature

WC = 35.74 + 0.6215T − 35.75V^0.16 + …

Apparent temperature combining ambient temperature and wind speed.

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Water Vapor Pressure

P_sat = 6.112 · exp(17.67·T / (T + 243.5))

Saturation water vapor pressure from temperature via the Magnus equation.

Calculate

Thermodynamics calculators covering the ideal gas law and its specific forms (Boyle's, Charles's, Gay-Lussac's, combined), heat capacity, and related thermal physics.

When to use these calculators

Use these for chemistry and thermodynamics problems involving gas behavior, phase changes, and heat transfer. Each shows the work step-by-step so students can follow the derivation.

Frequently Asked Questions

How does the calculator show its work?
Each calculator displays the substituted arithmetic step-by-step below the solution, so the user can verify the math by hand if needed. The 'Copy result' button captures the full formula → substitution → answer block.
Are the formulas cross-verified?
Every calculator's math has been cross-verified against textbook references and round-trip consistency tests (solve A from B, then solve B from A — the result must match the input). Spot-checks against Wolfram Alpha confirm the precision.
How do I switch between solving for different variables?
Most calculators in this category support multiple solve-for modes. Pick the unknown variable from the pill-toggle (or equation-card group) above the input fields, then enter the known values. The calculator auto-computes as you type.