Room Volume Calculator
Calculate room volume in cubic feet and cubic meters from length, width, and ceiling height.
Used for HVAC sizing, air purifiers, and ventilation planning.
Room Volume
Volume = Length × Width × Height
This calculator multiplies your room’s three dimensions together to find its total volume in cubic feet or cubic meters. Results are shown in both units regardless of which one you enter.
What the variables mean:
- Length – the longest wall of the room
- Width – the shorter wall of the room
- Height – floor to ceiling distance
When to use this calculator: Room volume is essential for several practical applications:
- HVAC sizing: Air conditioners and heaters are rated by the volume of space they can handle. An undersized unit will not cool or heat effectively.
- Air purifiers: Most purifiers list their coverage in cubic feet. Knowing your room volume ensures you buy the right size.
- Ventilation: Building codes require minimum air changes per hour based on room volume.
- Humidifiers and dehumidifiers: Capacity ratings are based on room volume.
Practical examples:
- A standard bedroom (12 ft × 10 ft × 8 ft) has a volume of 960 cu ft (27.2 m3).
- A large living room (20 ft × 15 ft × 9 ft) has a volume of 2,700 cu ft (76.5 m3).
- A small office (3.5 m × 3 m × 2.5 m) has a volume of 26.25 m3 (927 cu ft).
Tips:
- Measure to the nearest half-foot or 10 cm for accurate results.
- For rooms with cathedral or vaulted ceilings, use the average ceiling height.
- The calculator also shows your floor area, which is useful for flooring and carpet estimates.
- If your room is L-shaped, calculate each rectangular section separately and add the volumes together.