Area Calculator
Find the area of any rectangle in seconds. Enter its length and width in the same unit and the page returns length times width, which works for floors, walls, ceilings, garden beds, and slab footprints alike.
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Area Calculator online
Work out the area of a rectangle from its length and width — for floors, walls, plots and material estimates — in whatever unit you measure in, with notes on the shapes and purchases where a single multiplication is not the whole story.
How it works
The calculation is Area = Length × Width. The two inputs carry no fixed unit — the answer is in square units of whatever you typed. Enter metres to get square metres, feet to get square feet. The only rule is consistency: if length is in metres and width in centimetres, divide the centimetre figure by 100 first.
Worked example
A bedroom floor 5.5 m by 4 m: area = 5.5 × 4 = 22 m². Allowing 10% cutting waste for flooring gives 22 × 1.10 = 24.2 m² to buy. In imperial units, an 18 ft by 12 ft room gives 18 × 12 = 216 ft²; since 1 m² = 10.7639 ft², the 22 m² room equals about 236.8 ft².
Units
Common conversions: 1 m² = 10.7639 ft² = 1.196 yd²; 1 ft² = 0.0929 m². For paint-style coverage, divide the area by the product’s coverage rate — for example, 22 m² at 10 m² per litre needs 2.2 litres per coat, so buy 5 litres for two coats. For L-shaped rooms, split the plan into two rectangles, run each here, and add the results.
Practical tips
- Measure wall-to-wall at floor level in two places each way; older rooms are rarely square, so use the larger reading for material orders.
- Deduct large openings (doors, stairwells) only when they exceed about 1 m²; chasing fractional deductions usually causes more errors than it saves.
- Photograph the tape against the wall for each reading so you can re-check figures when ordering later.
- Treat the answer as a neat geometric area. Joist spacing, pattern matching, and subfloor repairs can change the material actually needed, so confirm against supplier guidance or professional advice for large orders.
Edge cases and limitations
- Triangles and circles. This page multiplies length × width. For a triangle use ½ × base × height (a 6 m × 4 m gable end is 12 m², not 24); for a circle use π × r² (a round rug of radius 1.5 m covers about 7.07 m²). L-shaped rooms: split into two rectangles and add — measuring the bounding box and subtracting the missing corner works too.
- Feet and inches. Convert the inches first: 10 ft 6 in is 10.5 ft, so a 10 ft 6 in × 8 ft floor is 84 ft². Typing 10.6 inflates the answer by about 1%.
- Roll goods break the waste rule. The worked example adds 10% for flooring, but carpet and vinyl come in fixed roll widths (often 3.66 m or 4 m): a 3.8 m wide room forces a 4 m roll and the offcut is waste whether you planned it or not. Check the area against the roll width, not just the percentage.
- Area is not quantity. Paint, tiles and boards each convert area to product differently (coverage rates, box sizes, sheet goods). Use this page for the square measure, then the dedicated calculator for the purchase quantity.
Privacy and browser processing
The calculation runs entirely in your browser — the dimensions you enter are never uploaded.
Frequently asked questions
How do I calculate the area of an L-shaped room?
Split it into two rectangles and add them. If one leg is 5 × 3 m (15 m²) and the other is 2 × 3 m (6 m²), the total is 15 + 6 = 21 m². Run each rectangle through the tool separately, then add the two answers.
Why is my answer 100 times too big?
You almost certainly mixed metres and centimetres — for example 5.5 m × 400 instead of 5.5 × 4. Because 400 cm = 4 m, the fix is 5.5 × 4 = 22 m². Convert every input to the same unit before typing.
How much laminate should I buy for 22 m²?
Add the product-specific waste: 22 × 1.05 = 23.1 m² for straight plank lays, or 22 × 1.10 = 24.2 m² for diagonal or tiled patterns. Then round up to whole packs — if a pack covers 2.5 m², 24.2 ÷ 2.5 = 9.68, so buy 10 packs (25 m²).
Can I enter feet and inches together?
Convert to a single decimal first: 12 ft 6 in = 12.5 ft. A wall 12.5 ft by 8 ft gives 12.5 × 8 = 100 ft². To metricate, multiply ft² by 0.0929, so 100 ft² ≈ 9.29 m².