Square Meters Calculator

What the square meters calculator does

Square meters is the area unit most of the world prices flooring, land, and materials in, so for many jobs it is the figure on the quote. This works it out. You pick a shape, enter its size, and it returns the area in square meters, with a quantity and a price if you want them.

It handles four shapes and takes imperial measurements too, so it doubles as a converter. Below is how it works.

How to use it

1. Pick the shape: rectangle, square, circle, or triangle.
2. Enter its size for that shape, each measurement with its unit, mixing metric and imperial freely.
3. Set a quantity or add a price if you need them, then press Calculate, or Reset to clear it.

How the area is worked out

Each shape has its own area formula, and the calculator converts your measurements to meters first, so the answer lands in square meters whatever unit you enter. For a rectangle, the simplest case:

Square meters = length × width

A quantity multiplies that by however many identical shapes you have, and a price totals the cost. For a space that is not one shape, work out each part and add them.

The four shapes

The shapes cover the common outlines. A rectangle is length times width, and a square is a side times itself. A circle uses pi times the radius squared, worked from the diameter, for round areas.

A triangle is found from its three side lengths rather than a base and height, which suits measuring a real plot where the height is awkward to pin down. Pick the shape that matches what you are measuring and the calculator uses the right formula for it.

Square meters in other units

Because the calculator accepts feet and inches as well as metric, it converts as it goes: measure in imperial, read the answer in square meters. The relationship is worth knowing in case you need to cross-check. One square meter is about 10.76 square feet, a good deal more than a square yard, which is about 0.84 of a square meter.

That larger jump than you might expect, a square meter being well over ten square feet, comes from squaring the length difference between a meter and a foot. So a room that sounds modest in square meters is a fair bit bigger in square feet, which is handy to keep straight when comparing quotes in different units.

A worked example: a 4 by 5 m room

Say the room is a rectangle 4 meters by 5 meters.

The area is 4 × 5 = 20 square meters. In imperial that is about 215 square feet, since each square meter is roughly 10.76 square feet.

So the same floor is 20 square meters or about 215 square feet, depending on which unit the flooring is priced in.

Questions people ask

How do I calculate square meters?

For a rectangle, multiply length by width in meters. A 4 by 5 meter room is 20 square meters. Other shapes use their own formulas, which the calculator applies.

How many square feet are in a square meter?

About 10.76, so a square meter is much larger than a square foot. A 20 square meter room is roughly 215 square feet.

Can I enter feet and inches?

Yes. The calculator converts imperial measurements to meters first, so it works as a converter as well as a calculator.

Does it do circles and triangles?

Yes. A circle uses pi times the radius squared, and a triangle is worked out from its three side lengths.

References

A quick note on the numbers. The areas are plain geometry: length times width for rectangles, pi times the radius squared for circles, and the three-side formula for triangles. The conversions to meters, and the relationship that a square meter is about 10.76 square feet, follow the US National Institute of Standards and Technology guide, where a foot is defined as exactly 0.3048 meters.

1. National Institute of Standards and Technology (NIST), Special Publication 811, Guide for the Use of the International System of Units (SI). https://www.nist.gov/pml/special-publication-811