How to Calculate Room Size
What is Room Size?
A room size calculator determines floor area, wall area, and volume. Essential for flooring, paint, wallpaper, and HVAC system sizing.
Formula
Step-by-Step Guide
- 1Floor area = Length × Width
- 2Wall area = 2 × (Length + Width) × Height
- 3Volume = Length × Width × Height
- 4For paint: deduct doors/windows (~20%); divide by coverage per litre
Worked Examples
Frequently Asked Questions
What is Room Size?
A room size calculator determines floor area, wall area, and volume. Essential for flooring, paint, wallpaper, and HVAC system sizing
How accurate is the Room Size calculator?
The calculator uses the standard published formula for room size. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.
What units does the Room Size calculator use?
This calculator works with inches, percentages, watts. You can enter values in the units shown — the calculator handles all conversions internally.
What formula does the Room Size calculator use?
The core formula is: Floor area = Length × Width. Each step in the calculation is shown so you can verify the result manually.
Ready to calculate? Try the free Room Size Calculator
Try it yourself →