An L-shaped room looks intimidating to measure until you stop treating it as one odd shape and start treating it as one simple shape with a bite taken out.
Measure the room as if the missing corner weren't there — a full 5m × 4m rectangle, 20 m². Then measure just the missing corner on its own — 2m × 1.5m, 3 m². Subtract:
| Step | Calculation | Result |
|---|---|---|
| Full bounding rectangle | 5m × 4m | 20 m² |
| Missing corner | 2m × 1.5m | 3 m² |
| Actual room area | 20 − 3 | 17 m² |
Two rectangle measurements, one subtraction — no need to break the room into two separate irregular pieces or trust a rough eyeball estimate of the total.
The same method extends cleanly: measure the full bounding rectangle once, then subtract each missing corner separately and sum the deductions. It scales to genuinely awkward layouts without the maths getting harder — just more subtractions.
Rectangle, L-shape or circle — get the exact area and flooring box count in one go.
Use the Room Area Calculator →