Area and Volume Calculator
Choose a shape, enter its measurements and see its area, perimeter, volume or surface area. Pick the units you measured in, and the units you want the answer in.
Dieser Inhalt ist auf Englisch.
Answers use pi (π) and are rounded to two decimal places. Volumes are given in cubic units and areas in square units, and a solid's surface area covers all of its faces or curved surface.
Durchgerechnete Beispiele
Area and perimeter of a room
Rectangle 5 m by 3 m
Area 15 m² and perimeter 16 m.
Area is length times width, and perimeter is the sum of all four sides, so 5 + 3 + 5 + 3 gives 16.
Area of a circle
Circle with a radius of 2 cm
Area about 12.57 cm².
The area is pi times the radius squared, so 3.14159 times 4 is about 12.57.
Über Area and Volume Calculator
Area tells you how much flat space a shape covers, while volume tells you how much room a solid takes up. Both are needed for everyday jobs such as buying turf or paint, filling a tank with liquid, sizing a container or estimating how much concrete a foundation needs. This calculator covers the common shapes: rectangles, triangles, circles and trapezia for area, and cuboids, cylinders, spheres and cones for volume and surface area. Choose a shape, type its measurements, and the answer appears as you type.
Units matter. A measurement in centimetres gives an area in square centimetres, and dividing that by 10,000 converts it to square metres. The units selector handles the conversion for you, so you can measure in one unit and receive the answer in another, such as square feet for a room measured in metres. Results use pi, rounded to two decimal places, and include the perimeter, circumference or slant height where relevant. That way you can see the full set of figures for a shape in one place, rather than working each one out separately.
So verwenden Sie Area and Volume Calculator
- Choose the shape you need from the list.
- Enter each measurement in the box beside its label, all in the same length unit.
- Choose the unit you measured in, and the unit you want the answer in if it is different.
- Read the area or volume, along with any perimeter, surface area or slant height.
Typische Einsatzzwecke
- Working out how much paint or turf a wall or lawn needs
- Estimating the volume of a water tank or a cylindrical container
- Calculating how much concrete a round or rectangular base requires
- Checking the surface area of a box for wrapping or packaging
Häufige Fragen
What is the difference between area and volume?
Area measures the flat surface inside a two-dimensional shape and is given in square units, such as m². Volume measures the space inside a three-dimensional solid and is given in cubic units, such as m³. A floor is measured by its area, while the air in a room is measured by its volume. Surface area measures the outside of a solid, so the wrapping for a box needs its surface area, not its volume.
How do you find the area of a triangle?
Multiply the base by the perpendicular height, then divide by two. The height must be measured straight up from the base, at a right angle, not along a slanted side. A triangle with a base of 10 and a height of 4 has an area of 20. The formula works for any triangle, including those that lean to one side.
What is the slant height of a cone?
The slant height is the distance from the tip of the cone down its side to the edge of the base. It is found with Pythagoras, using the radius and the vertical height, so the slant height equals the square root of the radius squared plus the height squared. A cone with a radius of 3 and a height of 4 has a slant height of 5. The slant height is needed to work out the curved surface area.
Why are the answers in square or cubic units?
Area is a two-dimensional measure, so it is worked out in squares, and volume is three-dimensional, so it is worked out in cubes. When you change units, the area changes by the square of the length conversion, and the volume by the cube of it. A square measuring 100 cm by 100 cm has an area of 10,000 cm², which is exactly 1 m², so the calculator handles this for you.
Is pi exact in these answers?
No. Pi is an endless decimal, roughly 3.14159, and the calculator uses its full value before rounding the answer to two decimal places. For most practical jobs the two-decimal answer is more than precise enough. If you need an exact answer for a science or engineering project, keep the result in terms of pi until the final step.