Room Volume Calculator
Calculate a room's square footage and cubic volume — useful for HVAC sizing, moving, storage planning and heating or cooling estimates.
Result
Enter your numbers to see the estimate.
How this calculator works
Room volume comes up more often than you'd expect: HVAC contractors use it to size heating and cooling equipment, movers and storage companies use it to estimate space needs, and it's a handy number when comparing air purifiers or humidifiers rated by room size.
The calculation is straightforward: square footage = length × width, and cubic footage (volume) = length × width × height. This calculator gives you both, plus a cubic meter conversion for products or specs that use metric units.
If you're using this for HVAC sizing, note that contractors also factor in insulation quality, window count, ceiling height variance and climate zone — this calculator gives you the raw room volume as a starting input, not a full load calculation. For moving and storage, cubic footage is a useful proxy for how much "space" a room's contents will need in a truck or storage unit.
Example: A 12 ft × 10 ft room with 9 ft ceilings has 120 sq ft of floor area and 1,080 cubic feet of volume (about 30.6 cubic meters).
How it works
Enter your measurements or costs
Fill in the room size, materials or costs for your project. No sign-up required.
Adjust the settings
Choose your units, waste percentage and any project-specific options.
Get your estimate instantly
See your results calculated instantly, right in your browser.
Frequently asked questions
How do I calculate room volume?
Multiply length × width × height, all in the same unit, to get cubic feet (or cubic meters). This calculator does the conversion for you.
Why does room volume matter for HVAC?
Heating and cooling equipment is sized partly based on the volume of air it needs to condition. This calculator gives you the raw volume; a full HVAC load calculation also factors in insulation, windows and climate.
Is this useful for moving?
Yes, room volume is a useful proxy for how much truck or storage space a room's contents will need, alongside our dedicated moving box calculator.
What's the difference between square footage and cubic footage?
Square footage is floor area (length × width) — a 2D measurement. Cubic footage is volume (length × width × height) — a 3D measurement that includes ceiling height.
Can I use this calculator for irregular rooms?
This calculator assumes a simple rectangular room. For L-shaped or irregular rooms, split the room into rectangular sections and calculate each separately, then add the results together.