Area of a L-shaped room calculator
Enter the dimensions of a L-shaped room and read off its area, its perimeter and the quantities that follow from them.
Area
21m²
- Perimeter
- 20
- Area removed
- 3
Show the working
- Overall length = 6
- Overall width = 4
- Cut-out length = 2
- Cut-out width = 1.5
- Area = 6*4 - 2*1.5 = 21
- Perimeter = 2*(6 + 4) = 20
- Area removed = 2*1.5 = 3
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- area = overall rectangle - cut-out rectangle
- the perimeter of an L is the same as its bounding rectangle
The perimeter really is unchanged by the notch: the two inward edges replace exactly the two they removed.
Lengths are entered in metres by default; switch any field to feet, inches or millimetres and the conversion is exact.