Room Area Calculator
Calculate floor, wall and ceiling areas plus room volume.
Please note: Material estimates for planning only. Always confirm quantities against your drawings, local building codes and supplier specifications before ordering. Structural work requires a qualified engineer.
What the Room Area Calculator does
A room measurement drives every other trade estimate: floor area for flooring, wall area for paint and plaster, perimeter for skirting, and volume for heating. This calculates all of them from three dimensions.
Formula
Floor area = Length × WidthPerimeter = 2 × (Length + Width)Wall area = Perimeter × Height − OpeningsVolume = Floor area × Height
Inputs explained
| Input | Unit | Required | Notes |
|---|---|---|---|
| Room length | number | Yes | Accepts more than 0. |
| Room length unit | one of 6 options | Yes | — |
| Room width | number | Yes | Accepts more than 0. |
| Room width unit | one of 6 options | Yes | — |
| Ceiling height | number | Yes | Accepts more than 0. |
| Ceiling height unit | one of 6 options | Yes | — |
| Total opening area | m² | Optional | Accepts 0 or more. |
How to use it
- Choose Room length unit and Room width unit.
- Enter Room length, Room width and Ceiling height.
- Optionally add Total opening area.
- Select Calculate.
Worked example
A 5 m × 4 m room with a 2.4 m ceiling and 5 m² of openings.
- Length
- 5 m
- Width
- 4 m
- Height
- 2.4 m
- Openings
- 5
Floor 20 m², perimeter 18 m, gross walls 43.2 m², net walls 38.2 m², volume 48 m³.
Frequently asked questions
Should I include the ceiling in wall area?
No — they are separate surfaces with different material needs. The calculator reports both and their combined total.