» 面积计算器


Area calculator for rectangle, triangle, circle, trapezoid, ellipse, sector, square, and more. Calculate square footage, land area, room area, wall area, and common geometry shapes with unit conversion.

Use this area calculator to find the area of common 2D shapes such as a rectangle, triangle, circle, trapezoid, square, ellipse, and more. It is useful for geometry, schoolwork, construction, flooring, tiling, room planning, wall coverage, and other situations where you need a quick area result in the right unit.

The page also works well as a practical square footage calculator, land area calculator, or room area calculator for simple shapes. Choose the shape, enter the known dimensions, and the calculator returns the area with matching unit conversion. For more specialized cases, you can switch directly to the dedicated shape calculator from the same menu.

For everyday use, the most common cases are room area, wall or floor coverage, garden and plot measurements, paint or tile estimates, and geometry exercises. If the shape is more complex, a common method is to split it into simpler shapes, calculate each area, and add the results.


圆面积公式

$$A= \pi \times r^{2}$$


提示: 输入任意一个已知值即可计算其余参数。如有需要,也可以输入 pi、1/2 pi、1 1/2pi 等带 pi 的表达式。


Area Calculator FAQ

What is an area calculator?
An area calculator finds the size of a two-dimensional shape. This page covers common shapes such as rectangles, triangles, circles, trapezoids, squares, sectors, ellipses, and more.

Can I use this as a square footage calculator or square meter calculator?
Yes. This page can be used as a square footage calculator or square meter calculator for rectangles and other simple shapes. Enter the dimensions, choose the unit, and the result can be shown in square feet, square meters, or another area unit.

Can I use this as a land area calculator or room area calculator?
Yes. It is useful for simple land area, room area, flooring, tiling, wall coverage, and coverage estimates when the space can be modeled as a rectangle, triangle, trapezoid, circle, or another supported shape.

What shapes does this area calculator support?
The calculator supports a range of 2D and surface-area cases, including rectangle, square, triangle, trapezoid, circle, sector, ellipse, parallelogram, rhombus, kite, regular polygon, and several 3D surface-area calculators from the same selector.

How do I calculate the area of an irregular shape?
A common method is to split the irregular shape into simpler parts, such as rectangles, triangles, circles, or trapezoids. Calculate each part separately, then add the areas together.

What units can I use in the area calculator?
You can choose the unit for the input dimensions and for the result. This makes it easy to work in metric or imperial units and convert the final answer to the area unit you actually need.

Which shapes are most common for practical area calculations?
For practical work, rectangles are the most common for rooms, flooring, and walls. Circles are common for round objects and plots, while triangles and trapezoids are useful for sloped or irregular sections.