Rectangle area
5 × 4
Area = length × width
Formula
Room length × room width
How the calculation works
Calculate a rectangular room’s floor area in square meters. Enter each measurement in the unit shown beside the input. The result updates when you change a value; incomplete or unsupported inputs display an explanation.
Worked example
A 5 m × 4 m room has 20 m² of floor area.
When to use this calculator
Split an L-shaped room into nonoverlapping rectangles and add their areas.
Common mistakes and limits
Measure at floor level. Do not add overlapping rectangles twice.
Check your result
Check that all measurements describe the same object or time period. Repeat the calculation with unrounded values, then round only the final quantity to a precision suitable for the task.
Frequently asked questions
Does this calculator need an account?
No. Calculations run in your browser without an account.
How precise is the displayed result?
The display rounds to six decimal places. Measurement uncertainty can be larger than this rounding.
