🌡️ Heat Transfer Coefficient Calculator
Calculate the convective heat transfer coefficient (h) from heat flow rate, surface area, and temperature difference.
W
m²
°C
What the heat transfer coefficient is
The convective heat transfer coefficient (h) quantifies how effectively heat moves between a surface and a surrounding fluid (air, water, etc.) through convection. It’s a key parameter in HVAC, thermal, and process engineering design.
The formula
Based on Newton’s law of cooling, Q = hAΔT, so h = Q / (AΔT), where Q is the total heat transfer rate, A is the surface area exposed to the fluid, and ΔT is the temperature difference between the surface and the fluid.
This gives an overall average coefficient; real heat transfer coefficients vary with fluid velocity, surface geometry, and flow regime (laminar vs. turbulent).
Last reviewed August 2026