Heat Transfer Convection Calculator

Summary

Enter the convection coefficient, surface area, and temperature difference to find the convective heat transfer rate using Newton's law of cooling.

How it works

1. Select a convection regime preset — free air convection, forced air, or water flow — to load a typical h value, or choose "Custom" to enter your own.
2. Enter the surface area (A) exposed to the fluid.
3. Enter the surface temperature and the fluid (ambient) temperature, then pick your temperature unit.
4. Click Calculate — the tool evaluates Q = h·A·ΔT and shows the heat transfer rate in watts.
5. Review the step-by-step breakdown to verify each substitution and unit conversion.
6. Use the Copy Result button to copy the result to your clipboard.

Use cases

• Estimating heat dissipation from an electronic component or heat sink.
• HVAC design — calculating heat loss from a hot surface to surrounding air.
• Engineering coursework on Newton's law of cooling and convection heat transfer.
• Comparing natural convection vs. forced convection for thermal management.
• Determining the required surface area or flow rate for a cooling system.
• Quick checks in thermal design before running detailed CFD simulations.

Frequently Asked Questions