SKY-001 / Engineering tools
Room & floor area calculator
Add rectangular rooms in meters, decimal feet or feet and inches. Calculate each room’s net area and the combined total in square meters and square feet.
Calculations run locally in your browser. Inputs stay on this page, and using the calculators requires no account or credits.
Live estimate
- Total area (m²)
- 18.00
- Total area (ft²)
- 193.75
| Room | Net area (m² / ft²) |
|---|---|
| Room 1 | 12.00 / 129.17 |
| Room 2 | 6.00 / 64.58 |
Worked example: an L-shaped room
How the calculation works
Room area = length × width. Total area = sum of all non-overlapping rectangles. Exactly 1 ft² = 0.09290304 m²; divide m² by 0.09290304 to obtain ft². Displayed results are rounded to two decimal places.
Starting example: a 4 × 3 m room and a 3 × 2 m room total 18 m², approximately 193.75 ft². Changing the dimension unit converts existing dimensions rather than reinterpreting their numbers.
Scope and assumptions
Measure internal clear room dimensions consistently. Add only non-overlapping rectangles; split L-shaped spaces into separate rectangles. This estimates net room area only, not gross floor area (GFA), floor area ratio (FAR), legal property area, a survey or building-code compliance. Walls, stairs, voids and local measurement rules need separate assessment.
Frequently asked questions
Can I mix feet and meters?
Each calculation uses one dimension unit for all rows. Convert measurements first or switch the unit selector, which converts the entered dimensions.
How do I measure an irregular room?
Divide it into rectangles that do not overlap. Curved or angled boundaries require a different geometry method; this tool does not approximate them automatically.
Can I use this for a permit or a property listing?
Not as a certified measurement. Legal and regulatory area definitions differ by jurisdiction. Use a qualified professional and the applicable measurement standard.