📐 Room Volume Calculator
Enter a room's length, width, and ceiling height to get its floor area and air volume — the measurements you need before sizing a radiator or heater.
🧮 Measure Your Room
What is a Room Volume Calculator?
It turns three tape-measure readings into the numbers heating sizing depends on. Enter length, width, and ceiling height and it returns the floor area in square feet and the air volume in cubic feet — the two figures every radiator and heater calculation starts from.
Use it as the first step in sizing heat for a room: take the volume into the radiator size calculator, or the floor area into the heating BTU calculator, and you'll pick equipment that matches the space instead of guessing.
❓ Frequently Asked Questions
How does the room volume calculator work?
Enter the room's length, width, and ceiling height in feet. The tool multiplies length by width to give the floor area in square feet, then multiplies that by the height to give the air volume in cubic feet.
Why do I need the volume of a room to heat it?
Radiators and many heaters warm the air, so their output is often specified per cubic foot of air rather than per square foot of floor. Two rooms with the same floor area but different ceiling heights hold different amounts of air and need different amounts of heat — volume captures that.
What about rooms that aren't a simple rectangle?
Split an L-shaped or irregular room into rectangular sections, work out each section's volume, and add them together. For a sloped or vaulted ceiling, use the average height across the room as a reasonable approximation.
What can I do with the result?
Drop the cubic-foot volume straight into the radiator size calculator to size a radiator, or use the floor area with the heating BTU calculator to estimate a room's heating requirement. It's the starting measurement for most heating sizing.