Area Converter

What an area converter does that a length converter cannot

Area is a length multiplied by a length, so every area factor is the square of a length factor. A foot is 0.3048 meter exactly, and one square foot is 0.3048 x 0.3048, or 0.09290304 square meter. That squared factor is the whole reason a 2,500 square foot house is 232.258 square meters and not 762 square meters.

The converter turns the number you type into square meters first, then divides by the factor of the unit you asked for. Square meters are the pivot because every other factor in the table is defined against them, which keeps the arithmetic to one multiplication and one division no matter which pair of units you pick.

The default example is a 2,500 square foot home. The same floor area is 232.258 square meters, 277.778 square yards, 360,000 square inches, 0.057392 acre, 0.023226 hectare and 0.00009 square mile. A hectare is 10,000 square meters, which is 2.4711 acres, so it is the unit that makes farmland and parks readable.

Read the table as a check on the arithmetic. A square yard holds 9 square feet, so 2,500 divided by 9 gives 277.778. A square inch is 1/144 of a square foot, so the same area is 2,500 x 144, or 360,000 square inches. When a conversion looks wrong, compare it against one of those two anchors before you doubt the tool.

The exact factors, unit by unit

Every factor below is exact, not a rounded decimal. The inch is 0.0254 meter by the 1959 agreement between the English speaking countries, the foot is twelve of those inches, the yard is three feet and the mile is 5,280 feet, so squaring those lengths gives exact areas. The International Bureau of Weights and Measures publishes the same definitions in the SI Brochure, where the hectare is listed among the units accepted for use with the SI. The federal guide to the SI, NIST Special Publication 811, lists the same factors in its appendix of conversion factors for area, including the square foot at 0.09290304 and the acre at 4.046 873 E+03 for the survey foot definition.

The acre is the one unit with a history. Until the end of 2022 the United States kept two feet: the international foot of 0.3048 meter and a survey foot of 0.3048006 meter used by mapmakers. NIST and the National Geodetic Survey retired the survey foot on 31 December 2022, and the notice that retired it defines the acre as 4,046.8564224 square meters from that date. The old survey acre was 4,046.8726099 square meters, a difference of 0.0162 square meter per acre, or about 16 square meters on 1,000 acres.

This converter uses the international acre, the one in force for every deed and plat recorded since 2023. If you are checking a boundary survey drawn before that date, the survey acre figure is the one on the paper, and the difference will show up in the fourth decimal place of a hectare conversion.

Square feet, square meters and price per area

Real estate is where the two systems meet most often, because a listing in the United States quotes square feet and a listing in most of the rest of the world quotes square meters. An 1,800 square foot apartment is 167.225 square meters. A 95 square meter apartment is 1,022.57 square feet. Neither number is more accurate than the other, since both come from the same measurement.

Price is where the conversion earns its keep. A home priced at $450,000 with 2,500 square feet costs $180.00 per square foot, which is $1,937.50 per square meter. The multiplier is 10.7639, the number of square feet in a square meter, so a price per square foot times 10.7639 gives the price per square meter, and a price per square meter times 0.09290304 gives the price per square foot.

Run the reverse case to see how much the unit changes the look of a price. At $2,000 per square meter the same space costs $185.81 per square foot, so a market that quotes 200 dollars a foot and a market that quotes 2,000 dollars a meter are describing almost the same price. Type 1 into the converter, set the unit you have to square meters, set the unit you want to square feet and enter 2,000 as the price to see that line.

One caution on listings: floor area is measured to the outside of the walls in some countries and to the inside in others, and a balcony may or may not count. A 10 percent gap between two quoted areas is more often a measurement rule than a conversion error.

Acres, hectares and land listings

Land is sold in acres in the United States and in hectares almost everywhere else, and the two are close enough to confuse at a glance: one hectare is 2.4711 acres, so a 40 hectare farm is 98.842 acres, not 40. The table below keeps the common parcel sizes on one line.

A 12.5 acre parcel is 544,500 square feet, 50,585.71 square meters and 5.0586 hectares. Half a hectare is 1.2355 acres, and 0.4 hectare is 0.988422 acre, which is the useful rule of thumb that a hectare is two and a half acres and a square 100 meters on a side.

The 640 acre row is worth remembering because it is a section, one square mile, the grid unit of the public land survey used across much of the western United States. A quarter section is 160 acres, and a quarter of that is 40 acres, the size that gives the phrase forty acres and a mule its shape.

At the other end of the scale, a city of 468 square miles covers 1,212.11 square kilometers. Square miles to square kilometers is the one conversion in this table where the number gets smaller as the unit gets bigger in a way people notice, because 1 square mile is 1.609344 kilometers on a side, which is 2.59 square kilometers.

The unit mistakes that cost money

The expensive errors are not arithmetic, they are unit errors. The first is treating a linear measure as an area. A lot 100 feet wide and 150 feet deep is 15,000 square feet, which is 0.344353 acre and 1,393.55 square meters, but a quote for 100 feet of fencing covers one edge of it. Fencing, edging and skirting are priced by the linear foot, flooring and sod by the square foot.

The second is forgetting that a square yard is nine square feet, not three. Carpet is sold by the square yard in the United States, so 500 square yards of carpet is 4,500 square feet, or 418.064 square meters. A room 15 feet by 20 feet is 300 square feet, which is 33.333 square yards, and ordering 300 square yards would carpet a house.

The third is the roofing square, a trade unit of 100 square feet that appears nowhere in the SI. A 30 square roof is 3,000 square feet, or 278.709 square meters. Roofing estimates also run the surface up a slope, so the plan area of the house is always smaller than the area of the roof.

The fourth is acre against hectare. Because 1 hectare is 2.4711 acres, a 100 acre field is 40.4686 hectares, and a 100 hectare field is 247.105 acres. Reading one as the other turns a 100 acre listing into a 40 acre listing, which is the kind of gap that ends a sale.

Picking a unit, and how many digits to keep

Match the unit to the size of the thing and to the audience. Floor plans in the United States are drawn in square feet, plans in Europe and Asia in square meters, carpet in square yards, tile in square feet or square meters, farmland in acres or hectares, and anything the size of a county in square miles or square kilometers. Mixing a small unit with a large object produces numbers nobody can read: 0.00009 square mile is correct for a house and useless.

Three significant digits is enough for a listing, four for a construction takeoff, and more than that only when you are checking someone else's arithmetic. Rounding 232.258 square meters to 232 square meters is a 0.1 percent change; rounding 2,500 square feet to 2,000 is a 20 percent change. Convert the rounded answer back to the original unit before you write it down, because a mistake in the factor survives every later step and a mistake in rounding does not.

Watch for a decimal slip in the other direction too. A 0.5 hectare lot is 1.2355 acres, and typing 5 instead of 0.5 turns it into 12.355 acres, which is a different property.

What this converter does not do

The converter multiplies one number by one factor. It does not measure a shape, so it cannot find the area of an L-shaped room, a triangle or a curved bed from a sketch. Split the shape into rectangles and triangles, convert each part, then add the parts in a single unit.

It does not handle slope. Area on a plan is the flat footprint, and the surface of a sloping roof or hillside is larger. A 10 percent slope adds about 0.5 percent to the surface, which is 12.5 square meters on a 2,500 square meter field, small enough to ignore for a lawn and not small enough to ignore for a roof order.

It does not convert volume, and it will not turn square feet into cubic yards for concrete or mulch. Those need a depth as a third dimension, which is a different calculation with its own tool.

The price field divides the total price by the area and nothing else. It does not add closing costs, commissions, taxes or a currency conversion, and it assumes the price and the area describe the same property. Use it to compare two listings on a common footing, then check the numbers against the listing sheet.

Finally, the factors are exact but the input is not. A deed written in survey feet, a floor plan measured to the outside wall and a listing that rounds to the nearest ten square feet all carry more uncertainty than the conversion does. Treat the output as a precise restatement of your input, not as a new measurement.