Who needs this?
Area shows up whenever someone is buying, selling, covering or comparing a flat surface:
- Home buyers and rentersA listing in Europe says 85 m², and you think in square feet.
- DIY and remodelingFlooring is sold by the square foot, carpet sometimes by the square yard, and the plans are in meters.
- Land buyersA lot is listed as 0.34 acres, a farm abroad as 40 hectares.
- Landlords and property managersRent per square foot only means something if everyone measured the same way.
- StudentsUnit-conversion problems with squared units are a classic place to lose points.
- Movers and storageA 10 × 10 storage unit is 100 ft², about 9.3 m².
Why area converts by the square
A meter is 3.28 feet. So a square that's 1 m on each side is 3.28 ft on each side, and its area is 3.28 × 3.28 = 10.76 ft². The length factor gets multiplied in twice because area has two dimensions.
Think of tiling a floor. Swap each big tile for small tiles a third as wide, and every big tile becomes three small ones across and three down: nine in all. That's why 1 yd² is 9 ft², not 3.
- 1 ft = 0.3048 m exactly, so 1 ft² = 0.3048² = 0.09290304 m² exactly.
- 1 m² = 10.764 ft² (1 ÷ 0.09290304).
- 1 yd² = 9 ft², about 0.836 m². 1 ft² = 144 in².
Converting, step by step
Square meters to square feet
Multiply by 10.764. If you have the room's dimensions in meters, you can also convert each side to feet first and then multiply; you'll get the same answer.
- Multiply by 10.764
85 × 10.764 = 914.9 ft² - Or convert the sides first
4 m × 3.5 m = 13.12 ft × 11.48 ft ≈ 150.7 ft² (14 m²)
Measuring a room, including L-shapes
Measure wall to wall at floor level and multiply length by width. An L-shaped or irregular room is just several rectangles: draw a line that splits it into pieces, measure each one, and add them up. Closets and bay windows are their own small rectangles. Subtract the pieces you don't want (a kitchen island under new flooring, for example) the same way.
- Split the L into two rectangles
18 ft × 14 ft and 10 ft × 6 ft - Find each area
252 ft² and 60 ft² - Add them
252 + 60 = 312 ft² (about 29 m²)
Length: 18 ftWidth: 14 ftHow many: 1
Land: acres, hectares and square miles
An acre is 43,560 ft², about 4,047 m². It isn't a fixed shape: a square acre is about 208.7 ft on a side, but a long strip counts the same. A hectare is a square 100 m on each side (10,000 m²), about 2.47 acres. For whole regions, 1 square mile is 640 acres, or about 2.59 km².
Listing area vs usable area
The number on a listing and the floor you can actually walk on are rarely the same. Depending on the country, the market and the person doing the measuring, a figure might:
- be measured to the outside of the exterior walls, or to the inside face of the walls
- include or leave out stairwells, balconies, basements, attics or a garage
- count low-ceilinged space fully, partly or not at all
- for apartments, include a share of hallways, lobbies and other common areas
Standards differ between countries and even between local markets, so two homes both listed at 90 m² can feel quite different inside. When the size matters to you (comparing price per square foot, or ordering flooring), ask how it was measured, or measure the rooms yourself and add them up.
Real situations, worked out
85 × 10.764 = 914.9 ft². That's a comfortable two-bedroom by most American standards. Keep the section above in mind: the usable floor may be noticeably smaller than the listed figure.
85 m² ≈ 915 ft²12 × 14 = 168 ft². Carpet priced by the square yard: 168 ÷ 9 = 18.67 yd². Add 10% for seams, trimming and pattern matching: 18.67 × 1.1 = 20.53, so plan on about 21 yd² (or 185 ft²). The construction estimates guide covers how much waste to allow for different materials.
168 ft² = 18.67 yd² → order about 21 yd²Length: 14 ftWidth: 12 ftExtra for waste: 10%Price (optional): $0.00Price is per: ft²
100 × 150 = 15,000 ft². Divide by 43,560 to get acres: 0.344. In metric, 15,000 × 0.0929 = 1,393.5 m², about 0.14 ha.
15,000 ft² ≈ 0.34 acre40 × 2.471 = 98.84 acres, so just under 100. For a picture of the size: an American football field including the end zones is 360 × 160 ft = 57,600 ft², about 1.32 acres, so 40 ha is roughly 75 football fields.
40 ha ≈ 98.8 acresDoing it in your head
For square meters to square feet, multiply by 11. It comes out about 2% high, which is fine for sizing up a listing. Going back, divide square feet by 11 (about 2% low). For land, hectares × 2.5 = acres is about 1% high, and acres × 0.4 = hectares is about 1% low.
| From | Exact | Quick rule | Off by |
|---|---|---|---|
| 20 m² | 215.3 ft² | 220 ft² | 2.2% |
| 50 m² | 538.2 ft² | 550 ft² | 2.2% |
| 100 m² | 1,076.4 ft² | 1,100 ft² | 2.2% |
| 2 ha | 4.94 acres | 5 acres | 1.2% |
| 10 ha | 24.71 acres | 25 acres | 1.2% |
| 40 ha | 98.84 acres | 100 acres | 1.2% |
Picture an acre. A football field without the end zones (300 × 160 ft) is 48,000 ft², about 1.1 acres. So an acre is a little over 90% of the playing field, goal line to goal line.
Common mistakes
Using the length factor for area. 50 m² × 3.28 = 164, which looks plausible and is wrong by a factor of more than three. The right answer is 50 × 10.764 = 538 ft². If you only remember 3.28, square it first.
Dividing by 3 to get square yards. A square yard is 3 ft × 3 ft = 9 ft². A 168 ft² room is 18.67 yd², not 56.
Confusing "10 feet square" with "10 square feet". "10 feet square" means a square 10 ft on each side, which is 100 ft². "10 square feet" is a tenth of that. Plans and listings use both phrasings.
Writing 12 ft 6 in as 12.6. Six inches is half a foot, so it's 12.5 ft. A 12 ft 6 in × 10 ft room is 125 ft², not 126. The length guide has more on decimal feet.
A bit of history
The acre is older than any of the units used to define it today. In medieval England it was roughly the land a team of oxen could plow in a day, and it was later fixed as a strip one furlong long and one chain wide.
- 1620English mathematician Edmund Gunter introduces the 66-foot surveyor's chain. Ten square chains (one chain by one furlong, 66 × 660 ft) make exactly one acre, 43,560 ft².
- 1785The Land Ordinance sets up the American grid survey: townships 6 miles on a side, divided into 36 sections of 1 square mile (640 acres) each.
- 1795France's new metric system introduces the are (100 m²) and the hectare (100 ares, 10,000 m²) for land.
- 1959The international foot is fixed at exactly 0.3048 m, which makes 1 ft² exactly 0.09290304 m².
- 2023The US survey foot, slightly longer than the international foot and long used for land surveys, is retired for new work.
Reference table
| Unit | Square feet | Square meters | Acres |
|---|---|---|---|
| 1 square inch | 0.00694 | 0.00064516 | |
| 1 square foot | 1 | 0.0929 | 0.000023 |
| 1 square yard | 9 | 0.8361 | 0.000207 |
| 1 square meter | 10.764 | 1 | 0.000247 |
| 1 are (100 m²) | 1,076.4 | 100 | 0.0247 |
| 1 acre | 43,560 | 4,046.86 | 1 |
| 1 hectare | 107,639 | 10,000 | 2.471 |
| 1 square kilometer | 10,763,910 | 1,000,000 | 247.1 |
| 1 square mile | 27,878,400 | 2,589,988 | 640 |
Questions people ask
How many square feet are in a square meter?
10.764. It's 3.2808 (feet in a meter) multiplied by itself. Going the other way, one square foot is 0.0929 m².
How big is an acre?
43,560 ft², or about 4,047 m². As a square, it's about 208.7 ft (63.6 m) on each side. It's a bit smaller than an American football field without the end zones.
How many acres are in a hectare?
About 2.471. One hectare is 10,000 m², and one acre is about 4,047 m².
How do I find the square footage of an L-shaped room?
Split it into two rectangles, multiply length by width for each, and add the results. An 18 × 14 ft area plus a 10 × 6 ft area is 252 + 60 = 312 ft².
How many acres are in a square mile?
Exactly 640. A square mile is 5,280 × 5,280 = 27,878,400 ft², and 27,878,400 ÷ 43,560 = 640.
Why is the listed size bigger than the rooms I measured?
Listings often measure to the outside of the walls and may include stairs, hallways or shared space. Your room-by-room total only counts open floor, so it's normally smaller.