Floor Area Of House Calculator

Work out floor area of house instantly with clear inputs, formula shown and shareable results.

About Floor Area Of House Calculator

Internal floor area is the sum of every room plus circulation space. The circulation share is a useful efficiency measure: below about 12% is very efficient, while above 20% suggests a lot of area is going into halls and landings rather than usable rooms.

Formula

Floor area

total = sum of room areas + circulation; 1 m2 = 10.7639 ft2

Worked example

With the default values below, Floor Area Of House Calculator returns Total internal floor area of 66.50. Change any input above and every figure here is recalculated in your browser.

Inputs used

Room 1 area: 24 m²
Room 2 area: 16 m²
Room 3 area: 12.5 m²
Hall, stairs and landing: 14 m²

Results

Total internal floor area: 66.50 m²
Total area: 715.80 ft²
Circulation share: 21.05% %
Habitable room area: 52.50 m²

Step by step

1Values used
2Floor area
3Total internal floor area= 66.50 m²
4Total area= 715.80 ft²
5Circulation share= 21.05 %
6Habitable room area= 52.50 m²

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Is this the same as gross internal area?

Close. GIA measures to the inside face of external walls and includes internal partitions, so it is slightly larger than the sum of room areas.

Why does circulation share matter?

You pay for it in build cost and heating but cannot furnish it. Efficient plans keep it low without making the house feel cramped.