Square meters is a measure of area commonly used to measure a flat space, such as a field or floor. For example, you can measure the size of a sofa in square meters and then measure your living room in square meters to see if it will fit. If you only have a ruler or measuring tape that uses feet or another non-metric measure, you can still calculate the area with it and convert it to square meters.
Method 1 of 3: Calculating an area in square meters
Step 1. Choose a measuring tape, ruler or measuring tape
Select a meter with meters (m) or centimeters (cm) printed on it. These tools will make it easier to calculate in square meters, as they were made using the same measurement system.
If you only find rulers with feet (ft) or inches (in), measure with them and go to the square meter conversion section
Step 2. Measure the length of the area you are measuring
Square meters is a unit for measuring the area or size of a two-dimensional object, such as a floor or a field. Use your measurement tool to measure one side of the object, corner to corner. Write down the result.
- If the object is larger than 1 meter, remember to also include the centimeters of the measurement; for example, 2 meters and 35 centimeters.
- If you want to measure an object that is not rectangular or square, read the complex shapes section instead.
Step 3. If you cannot measure the entire length at once, do it in parts
Place the measurement tool and then place a stone or other small object in exactly an easy-to-remember location (such as a 1-meter or 25-centimeter measurement). Take the tool and replace it, now starting from the object. Repeat until you cover the entire length and add up all measurements.
Step 4. Measure the width
Use the same tool to measure the width of the same area or object. The side you measure in this Step should be about 90 degrees away from what you measured earlier, like the two adjacent sides of a square. Write that number down, too.
Unless the object you are measuring is much smaller than 1 meter, you can round to the nearest centimeter when making your measurements. For example, if the width is just beyond the 1 meter and 8 centimeters mark, use only "1 m and 8 cm" as your measurement, without using decimal places or millimeter measurements
Step 5. Convert from centimeters to meters
Typically, measurements are not evenly divided into meters. Instead, you will have a measurement in meters and centimeters, for example: 2 meters and 35 centimeters. Since 1 centimeter = 0.01 meters, you can convert a centimeter measurement to meters by moving the decimal point two digits to the left. Here are some examples:
- 35 cm = 0.35 m, then 2 m and 35 cm = 2 m + 0.35 m = 2.35 m.
8 cm = 0.08 m, then 1 m and 8 cm = 1.08 m.
Step 6. Multiply the length by the width
After both measurements are converted to meters, multiply them to get the area measurement in square meters. If necessary, use a calculator. For example:
- 2.35 m x 1.08 m = 2.5272 square meters (m2).
Step 7. Round to a more convenient measurement
If you get a long decimal number as an answer, for example 2, 5272 square meters, you can round it to one with fewer digits, like 2, 53 square meters. In fact, since you didn't measure down to the smallest possible fraction of the meter, the last few digits probably won't be right anyway. In most cases, you can round to the nearest centimeter (0.01 m). For a more accurate measurement, learn to round to significant digits.
- Whenever you multiply two numbers in the same unit (for example, meters), the answer will be in the form of that unit squared (m2, or square meters).
Method 2 of 3: Converting Other Units
Step 1. Multiply square feet by 0.093
Measure the length and width in feet and multiply them to get a result in square feet. Since 1 square foot = 0.093 square meters, multiply the result by 0.093 to get the answer in square meters. These are larger than square feet, so fewer of them will cover the same area.
For greater precision, multiply by 0, 092903 instead
Step 2. Multiply square yards by 0.84
If you have the measurement in square yards, multiply it by 0.84 to get the equivalent in square meters.
For greater accuracy, multiply by 0.83613
Step 3. Multiply acres by 4050
One acre contains approximately 4050 square meters. If you want to be more precise, multiply by 4046, 9.
Step 4. Convert square miles to square kilometers
A square mile is much, much larger than a square meter, so it's usually converted to square kilometers. Multiply square miles by 2,6 to find area in square kilometers. (Or multiply by 2, 59 to be more precise).
If you really want to convert to square meters, 1 square kilometer = 1,000,000 square meters
Step 5. Convert square meters to units of area, not length
Square meters is a unit that measures area, or two-dimensional surfaces. It makes no sense to compare them with units that measure length or distance in one direction. You can convert between "square meters" and "square feet", but not between "square meters" and "feet".
Do not use the calculations in this section to convert between units of length. This requires different numbers
Method 3 of 3: Calculating the square footage of a complex shape
Step 1. Break the shape into pieces
If you're solving a math problem, draw or cut lines in the shape to divide it into simpler ones, such as rectangles and triangles. If you're measuring a room or other physical object, sketch a diagram of the area first and then do the same. Measure each section and record the measurements on the diagram. Follow the instructions below to find the area of each section and then add up the results.
Step 2. Measure the rectangular pieces as you normally would
To find the area in square meters for these sections, see the instructions on how to calculate an area in square meters.
If measuring in a different unit, check the section on other units
Step 3. Measure right triangles in the same shape and divide the result by two
A right triangle, which has a 90° angle just like the corners of a square, has an easy area to calculate. Measure both sides of the 90° angle (the length and the width), multiply one by the other, and divide by two to get the answer in square meters.
This works because a right triangle is exactly the size of a rectangle cut in half. Basically, you found the area of a rectangle, as usual, and then divided it by two to get the area of the triangle
Step 4. Turn other triangles into right triangles and measure them
Draw a line from any corner of a triangle to the opposite side so that it hits the opposite side at a 90° angle (imagine the corner of a square). You have just split the triangle into two parts, each a right triangle! Read the instructions above for instructions on finding the area of a triangle; measure each of the two subtriangles separately and add up the measurements.
Step 5. Calculate the area of a circle
The area of a circle is πr2, where r is the radius, or distance from the center of the circle to the edge, or perimeter. Measure this distance, multiply it by itself, and multiply the result by π on a calculator. If you don't have one with a π function, use 3, 14 (or 3, 1416, if high precision is needed).
- If you're not sure where the center is, have a friend hold the tape measure and walk around the edge of the circle. Hold the other end of the tape measure and adjust its position until the measurement stays the same as your friend walks around the entire edge.
- More complicated curved limits require more advanced math to calculate. If you are measuring a room for practical purposes, it may be easier to estimate the area by pretending that the curved regions are a series of straight lines.
- Say "five square meters" instead of "five meters squared". Technically, both are correct, but the second can be misinterpreted as the area of a 5 meter square (which will actually have an area of 25 square meters, or 5 x 5).
- If you are unsure of your calculations, check your answer with these measurements:
- A football field ranges from 4,000 to 11,000 square meters.
- An American football field is approximately 5,400 square meters.
- A king size mattress is about 5 square meters.