## How to calculate room area?

A room is a living space bounded on all sides by walls and equipped with a separate passageway. We suggest using the free tool from KALK.PRO, it will help you quickly estimate the total area of the room, by length and width of the floor/walls. The tool can only be used for square and rectangular shaped rooms, if you have a non-standard room, scroll just below. To start the calculation, enter the length of each wall of the room: A, B, C, D and click "**Calculate**" to get the result.

## Room area calculation formulas

The area of a quadrilateral room in our online calculator is calculated using the Brahmagupta formula:

**S**, where_{room}= ((p − a) × (p − b) × (p − c) × (p − d))^{1/2}*a, b, c, d*– sides of a quadrangle,*p*– half-perimeter of a quadrilateral (which is based on the formula:**p = (a + b + c + d) / 2**).

If you want to calculate the area of a room with five, six or more walls - the easiest way is to divide the room surface into simple shapes (square, rectangle, triangle, trapezium), use standard mathematical formulas and add up the values.

- Triangular room area formula:
**S = (a × h) / 2**, where*а*– base,*h*– height. - Square room area formula:
**S = a**, where^{2}*а*– side. - Rectangular room area formula:
**S = a × b**, where*а, b*– sides. - Trapezoid room area formula:
**S = ((a + b)****× h)****/ 2**, where*a, b*– bases,*h*– height.