Room Volume Calculator
Calculate a room's volume in cubic feet and cubic meters from its length, width, and height.
Room Volume
1080.0 cu ft
30.58 cu m
How to Calculate Room Volume
Room volume is simply length times width times height, giving the total amount of air space enclosed by the room. This figure is more useful than floor area alone for sizing HVAC equipment, ventilation, and air purifiers, since taller rooms have more air to heat, cool, or filter than the floor area suggests.
Example
A room measuring 12 ft × 10 ft with a 9 ft ceiling has a volume of 12 × 10 × 9 = 1,080 cubic feet, which is about 30.6 cubic meters.
Common Use Cases
- Sizing an air conditioner, heater, humidifier, or air purifier to a room's actual air volume.
- Estimating how many air changes per hour a ventilation system provides for a room.
- Comparing rooms with different ceiling heights that have the same floor area.
FAQs
Why does volume matter more than floor area for HVAC sizing?
Heating, cooling, and air purification all work on the volume of air in a space, not just its floor footprint. A room with a 12-foot ceiling has 33% more air to condition than an identical-footprint room with a 9-foot ceiling, which directly affects the equipment capacity you need.
How do I handle a room with a sloped or vaulted ceiling?
For a sloped ceiling, use the average height across the room as an approximation, or split the room into simpler rectangular and triangular sections, calculate each volume separately, and add them together for a more accurate total.
What units does this calculator use?
Enter length, width, and height in feet, and the result shows both cubic feet and the metric equivalent in cubic meters, so you can use whichever unit your HVAC equipment or specifications reference.