Heat transfer, entropy, thermal expansion, and calorimetry calculators. Browse our free thermodynamics tools below — all calculators are instant, accurate, and require no sign-up.
Absolute Humidity Calculator — Calculate absolute humidity from temperature and relative humidity. Find moisture content in grams per cubic meter for HVAC, weather, and climate analysis.
Altitude Temperature Calculator — Calculate temperature at any altitude using ISA lapse rate. Find atmospheric pressure, air density, and boiling point changes for aviation and mountaineering.
Black Hole Temperature Calculator — Calculate Hawking temperature of a black hole from its mass. Find event horizon radius, evaporation time, luminosity, and entropy using black hole thermodynamics.
BTU to Tons of Refrigeration Converter — Convert BTU/hr to tons of refrigeration and back. Calculate HVAC cooling capacity, energy costs, and efficiency ratings for air conditioning system sizing.
Calorimetry Calculator — Calculate heat exchange and final equilibrium temperature using Q = mcΔT. Solve calorimetry problems with material database and entropy calculations.
Carnot Efficiency Calculator — Calculate maximum Carnot efficiency for heat engines. Compare ideal vs actual efficiency, find COP for heat pumps, and analyze thermal power cycles.
Dew Point Calculator — Calculate dew point temperature from air temperature and relative humidity using the Magnus formula. Includes comfort scale, wet bulb, cloud base estimation.
Enthalpy Calculator — Calculate enthalpy using H = U + PV. Find enthalpy change, formation enthalpies, and combustion enthalpies with unit conversions and reference data.
Ideal Gas Density Calculator — Calculate gas density using ρ = PM/(RT). Find density of any gas from pressure, temperature, and molar mass with built-in gas database and unit conversions.
Ideal Gas Law Calculator (PV = nRT) — Solve PV = nRT for any variable. Calculate pressure, volume, moles, or temperature of ideal gases with full unit conversions and gas property calculations.
Ideal Gas Pressure Calculator — Calculate gas pressure using P = nRT/V. Find pressure from moles, temperature, and volume with multi-unit output and gas property calculations.
Ideal Gas Temperature Calculator — Calculate gas temperature using T = PV/(nR). Find temperature from pressure, volume, and moles with all temperature scales and molecular kinetics.
Ideal Gas Volume Calculator — Calculate gas volume using V = nRT/P. Find volume from moles, temperature, and pressure with multi-unit results and container size comparisons.
Joule Heating Calculator — Calculate resistive heating energy using Q = I²Rt. Find power dissipation, voltage drop, and wire properties for electrical heating applications.
Latent Heat Calculator — Calculate energy for phase changes using Q = mL. Find heat of fusion and vaporization for 10 substances with energy breakdowns and comparison tables.
Mixed Air Temperature Calculator — Calculate mixed air temperature from 2-3 airstreams in HVAC systems. Find weighted average temperature, flow fractions, and mass flow rates.
Psychrometric Calculator — Calculate psychrometric properties from dry-bulb and wet-bulb temperatures. Find RH, humidity ratio, enthalpy, dew point, and air density for HVAC design.
Relative Humidity Calculator — Calculate relative humidity from dry-bulb + wet-bulb, dew point, or absolute humidity. Find RH, humidity ratio, dew point, and enthalpy.
Sensible Heat Calculator — Calculate sensible heat transfer rate using Q = mass flow × cp × ΔT. Find heating/cooling loads in kW, BTU/h, and tons for HVAC and process engineering.
Specific Heat Calculator — Calculate specific heat capacity from Q, m, and ΔT. Solve for cp, energy, mass, or temperature with a 17-material database and comparison charts.
Stefan-Boltzmann Law Calculator — Calculate thermal radiation power using P = εσAT⁴. Find radiated power, net heat transfer, peak wavelength, and spectrum position for any temperature.
Thermal Conductivity Calculator — Calculate heat flow using Fourier law q = kAΔT/L. Find R-value, U-value, and heat flux for 14 materials with visual conductivity comparison.
Thermal Diffusivity Calculator — Calculate thermal diffusivity α = k/(ρcp), Fourier number, penetration depth, and characteristic time for 12 materials with visual comparison.
Thermal Efficiency Calculator — Calculate thermal efficiency for Carnot, Otto, Diesel, Brayton, and Rankine cycles. Compare actual vs ideal efficiency with energy flow visualization.
Thermal Equilibrium Calculator — Find the final equilibrium temperature when 2-5 bodies with different materials and temperatures reach thermal equilibrium. Visual convergence display.
Thermal Expansion Calculator — Calculate linear, area, and volumetric thermal expansion for 13 materials. Find ΔL = αLΔT, thermal stress, and compare CTE across materials.
Van der Waals Equation Calculator — Solve the van der Waals equation (P + an²/V²)(V − nb) = nRT for real gases. Find volume, compressibility factor Z, and compare with ideal gas behavior.
Virtual Temperature Calculator — Calculate virtual temperature Tv = T(1 + 0.61r) for moist air. Compare dry vs moist air density with humidity effects table and visualization.
Water Heating Calculator — Calculate energy, time, and cost to heat water for any volume. Supports 7 heater types, 4 energy prices, and common container comparison table.
Wet-Bulb Temperature Calculator — Calculate wet-bulb temperature from dry-bulb and relative humidity. Includes dew point, heat index, WBGT, heat stress risk assessment, and RH lookup table.
Wheatstone Bridge Calculator — Calculate unknown resistance using Rx = R3(R2/R1). Find bridge voltage, sensitivity, Thevenin equivalent, and explore balance conditions with visual diagram.