Area of a Rectangle Calculator
Multiply length by width. This is the formula behind almost every floor, wall and garden-bed measurement.
A = l × w
Perimeter: P = 2(l + w)
Area of the rectangle
96ft²
- Perimeter
- 40 ft
- A = l × w = 12 × 8 = 96 ft²
- P = 2(12 + 8) = 40 ft
Area in other units
| m² | 8.9187 |
| cm² | 89,186.9 |
| ft² | 96 |
| in² | 13,824 |
| yd² | 10.6667 |
| acres | 0.002204 |
| hectares | 0.000892 |
How to find the area of a rectangle
Formula: A = l × w. Perimeter: P = 2(l + w).
- Measure every length in the same unit. Mixing feet and inches is the most common mistake; convert first (6 in = 0.5 ft).
- Put the numbers into the formula above. The calculator shows each substitution with your numbers.
- Area comes out in square units (ft², m²). If you need a different unit, open "Area in other units".
Questions people ask
Does it matter which side I call length?
No. Multiplication is commutative, so 12 × 8 and 8 × 12 both give 96.
How do I get the diagonal of a rectangle?
d = √(l² + w²). A 12 × 8 rectangle has a diagonal of √208 ≈ 14.42.
Stuck on a word problem?
Paste a homework question or describe your project. The AI tutor names the formula and works it through step by step. Always check the result with the calculator above.
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