Appliances & Utilities calculator
What Space Heater Size Do I Need?
Find space-heater power from room volume, desired temperature rise, and heat-loss coefficient.
Enter your measurements
What Space Heater Size Do I Need? Measure room volume, desired temperature rise, and heat-loss coefficient first. This tool converts them into space-heater power so the recommendation stays tied to your actual dimensions or specification.
- Room volume — Required
- Desired temperature rise — Required
- Heat-loss coefficient — Required
Space-heater power
Enter the measurements above to calculate space-heater power.
How the calculation works
The engine follows this rule: requiredPower=roomVolume×temperatureRise×heatLossCoefficient. It returns space-heater power from the configured inputs.
Worked example
Example: Room volume = 45000 L; Desired temperature rise = 20 °C; Heat-loss coefficient = 50 W/m³·K. Result: Required Power = 45000 W.
Before you decide
Recheck the limiting measurement before purchase or installation. This page calculates the stated geometry or quantity only; product-specific construction or installation details can still affect the final choice. For what space heater size do i need, the limiting result on this page is space-heater power.
Direct measurement/geometry calculation. No external reference is required for the arithmetic itself; the result is derived only from the user-entered measurements and the formula stored in calculationLogicJson.
Frequently asked questions
What does the Space Heater Size calculator tell me?
It returns space-heater power from the measurements entered on this page. The calculation is specific to space heater size, so the result should be compared with the exact product or specification you are considering.
Which measurements should I take for space heater size?
Measure room volume, desired temperature rise, heat-loss coefficient. Use clear, usable dimensions rather than nominal room or product labels.
Should I round the space-heater power?
Keep the calculated value for comparison, then choose a real product that meets or stays within the returned space-heater power while allowing for the clearances, tolerances or ratings shown by its manufacturer.