Last updated: June 1, 2026

BTU Calculator

Calculate the BTU (British Thermal Unit) requirement for heating or cooling your room based on size and conditions.

Room Size (sq ft)

Ceiling Height (ft)

Insulation Quality

Sun Exposure

728 × 90 Leaderboard

320 × 100 Mobile Banner

336 × 280 Large Rectangle

300 × 250 Medium Rectangle

Related Calculators

Calculate appliance electricity costs per month and year.

Calculate how much fertilizer you need for your lawn.

Calculate your swimming pool volume in gallons and liters.

Calculate rolls of wallpaper needed for your room.

Estimate moving costs based on distance, home size, and services.

Estimate solar panel system size and savings for your home.

A British Thermal Unit (BTU) is a measure of heat energy. It's the standard unit used to rate heating and cooling equipment.

A general rule is 20 BTUs per square foot for cooling. Actual needs vary based on insulation, climate, and sun exposure.