How Much Square Footage Is in an Acre?

How many square feet are in an acre

One acre equals 43,560 square feet, which also works out to 4,840 square yards. That number comes from a fixed definition, not a shape, so an acre can be a perfect square, a long narrow strip, or any irregular lot, as long as the area adds up to 43,560 square feet.

To go the other way, multiply acres by 43,560 to get square feet: 0.5 acres is 21,780 square feet, and 2 acres is 87,120 square feet. If you already know your lot's length and width in feet, enter them in the square footage calculator to get the area in square feet, yards and acres at once.

Acre conversions: square yards, meters and hectares

Square feet is the most common way Americans see an acre written, but yards, meters and hectares come up too, especially on surveys, deeds and international listings.

Working the other direction, one hectare is about 2.47 acres, and one square meter is about 0.000247 acres. For a lot measured in meters, convert to square feet first, multiply by 10.7639, then divide by 43,560 to get acres.

What does one acre look like? Common acre dimensions

An acre has no fixed shape, only a fixed area, so its dimensions change with the lot. A perfectly square acre measures about 208.7 feet on each side, since 208.7 times 208.7 is close to 43,560 square feet.

Long, narrow acres are just as common, especially on older rural surveys. A strip 660 feet long by 66 feet wide is exactly one acre, and so is a 435.6 by 100 foot lot or a 330 by 132 foot lot.

For a lot that is not a simple rectangle, split it into rectangles and triangles the way calculate square feet calculator explains, then add the pieces before dividing by 43,560.

How an acre compares to a football field and other familiar spaces

An acre is smaller than a full football field. Including both end zones, an American football field measures 360 by 160 feet, or 57,600 square feet, about 1.32 acres.

Leave out the end zones and look only at the playing field, 300 by 160 feet, or 48,000 square feet, and one acre covers about 91% of it. Neither figure means a football field is exactly one acre; it is close, but always a bit larger.

Those comparisons help you picture a lot, but they will not give you your own property's exact size. A survey, plat map, or the length and width you measure yourself is what a real acreage figure depends on.

Common lot sizes as a fraction of an acre

Residential lots are often described as a fraction of an acre rather than in square feet. A quarter acre, a common suburban lot size, is 10,890 square feet, and a half acre is 21,780 square feet.

If you are sizing the house or addition that will sit on that lot rather than the land itself, square footage calculations covers the formula and size chart for rooms, garages and additions.

Where the acre came from: furlong, chain and medieval plowing

The acre is not an arbitrary round number. It comes from two older English survey units: a furlong, 660 feet, and a chain, 66 feet. Multiply them, 660 times 66, and the result is exactly 43,560 square feet.

Historically, an acre was meant to represent the area a team of oxen could plow in a single day, a strip one furlong long and one chain wide. That practical, long and narrow shape is why older rural parcels are so often laid out as strips rather than squares.

The unit survived into the US customary and imperial systems largely unchanged, which is why 43,560 still shows up on deeds and plat maps today instead of a rounder metric figure.

Converting your own lot's square footage to acres

To turn any lot into acres, measure its square footage first. For a rectangular lot, multiply length by width in feet; for an irregular lot, split it into rectangles and triangles, add the pieces, then divide the total by 43,560.

A 150 by 200 foot lot, for example, is 30,000 square feet, or 30,000 divided by 43,560, about 0.69 acres. A 300 by 300 foot lot is 90,000 square feet, about 2.07 acres.

The square footage calculator handles that conversion automatically for rectangles, squares, circles, triangles and bordered areas, showing square feet, yards, meters and acres together in one result.

Frequently asked questions

References

• Acre (Wikipedia)
• Furlong (Wikipedia)
• Chain, unit of length (Wikipedia)
• NIST: General Tables of Units of Measurement

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