Area Calculator
Area is the number every other material calculation starts from. Pick your shape, enter the measurements, and get the area in square metres or square feet along with the perimeter: and, if you enter a price, what the job will cost per square metre.
Your measurements
Check your order
Turn measurements into materials
- Keep each measurement and its unit with the sketch; exclude overlapping areas.
- Choose the material calculator next: an area or volume alone does not specify a pack count.
- Use the actual product coverage, thickness or bag yield before placing an order.
Tools for this job
Use a short tape for rooms and a longer tape for garden plots. Split irregular spaces into simpler shapes and record each measurement.
Affiliate links. As an Amazon Associate I earn from qualifying purchases. How this site is funded.
- Check room dimensions and cuts
Short tape measure
STANLEY 25-foot tape measure
For checking lengths, widths and short runs before ordering. This is a 25-foot tape; use matching units in the calculator and check the scale on the selected model.
View on Amazon.com May open your local Amazon store · opens a new tab Find alternatives on Amazon.nl Netherlands · search by tool type · opens a new tab - Measure longer outdoor runs
Long tape measure
Komelon 6611 100-foot open-reel tape
For measuring longer outdoor runs and marking out areas. Keep the tape straight and use the same units throughout; this listing is for the 100-foot model.
View on Amazon.com May open your local Amazon store · opens a new tab Find alternatives on Amazon.nl Netherlands · search by tool type · opens a new tab
Already have suitable tools? Reuse them. These are optional product suggestions, not a complete equipment list or a hands-on comparison. Amazon may redirect Amazon.com links to local products or search results. Amazon.nl links search for alternatives, which may differ in brand, size and specification. Check suitability, seller, delivery and any import costs on your chosen store before ordering.
Area formulas
Worked example
A rectangular room 5 m long and 4 m wide has an area of 5 × 4 = 20 m², or about 215 sq ft.
Its perimeter is 2 × (5 + 4) = 18 m. Use the area to order flooring and the perimeter to estimate skirting or edge trim.
How to measure a room properly
- Measure at floor level, along the skirting, not across the middle of the room where furniture gets in the way.
- Take each dimension twice, at both ends. If they differ, use the larger one: you can always cut material down, you cannot stretch it.
- Measure into every alcove, bay and doorway, and treat each as a separate rectangle.
- Write the measurements on a rough sketch as you go. Trying to remember four numbers on the way back to the laptop is how people end up ordering the wrong quantity.
- For an L-shaped room, use the L-shape option: enter the overall rectangle, then the piece that is missing.
Splitting an awkward room
Almost any real floor plan can be reduced to rectangles plus one or two triangles. Draw the plan, divide it with straight lines into shapes you recognise, calculate each and add them up. Use the number of identical areas field where several sections are the same size.
A bay window is normally a trapezoid: measure the two parallel sides (the wall opening and the outer face), and the depth between them.
A curved bay is close enough to a half-ellipse for material ordering. Use the ellipse option with the full width and twice the depth, then halve the result.
Common area conversions
| From | To | Multiply by |
|---|---|---|
| Square metres | Square feet | 10.764 |
| Square feet | Square metres | 0.0929 |
| Square yards | Square metres | 0.8361 |
| Square metres | Square yards | 1.196 |
| Hectares | Acres | 2.471 |
| Acres | Square metres | 4,046.86 |
| Square feet | Square yards | 0.1111 |
Why the perimeter matters too
Area tells you how much floor, paint or tile to buy. The perimeter tells you how much skirting, coving, edge trim, beading or expansion foam you need, and it is the figure people forget until they are standing in the aisle.
The calculator returns both wherever the shape has a meaningful perimeter. For skirting specifically, our skirting board calculator also deducts doorways and converts to whole boards.
Sources and assumptions
Results use elementary geometry: rectangles are length × width, triangles are half base × perpendicular height, circles are πr², and compound shapes add or subtract these areas. The three-side triangle option uses Heron’s formula.
Before using this estimate
- An L-shape is an outer rectangle with a rectangular corner removed. It does not describe every irregular floor plan.
- Ellipse perimeter is an approximation. Area does not include material waste, installation gaps or any allowance for measurements taken out of square.
Source notes reviewed . See how we check calculations and handle corrections.
Planning your order
Check the inputs before buying: measure the surfaces you need, then apply an allowance and round to whole packs. The guides include worked examples you can follow alongside this calculator.
Published by OrderEnough. This is a planning estimate: check the product specification and the assumptions above before ordering. Last updated . Read how we source our figures on the methodology page.