Built Up Area Calculator

Work out built up area instantly with clear inputs, formula shown and shareable results.

About Built Up Area Calculator

Carpet area is the usable floor inside the walls. Built-up area adds the wall thickness and balconies, typically about ten percent more. Super built-up area then adds a share of lobbies, stairs, lifts and services, the loading factor, which is why the area quoted in a sales brochure is well above what can be furnished.

Formulas

Built-up area

Built-up = carpet x (1 + wall allowance) + balcony

Super built-up

Super built-up = built-up x (1 + common area loading)

Worked example

With the default values below, Built Up Area Calculator returns Super built-up area of 133.75. Change any input above and every figure here is recalculated in your browser.

Inputs used

Carpet areaminimum 0.1 m²: 90 m²
Wall and duct allowanceaccepts 0–30 %: 10 %
Balcony and terrace areaminimum 0 m²: 8 m²
Common area loadingaccepts 0–60 %: 25 %

Results

Super built-up area: 133.75 m²
Built-up area: 107.00 m²
Area taken by walls: 9.00 m²
Carpet to super built-up ratio: 1.4861

Step by step

1Values used
2Built-up area
3Super built-up
4Super built-up area= 133.75 m²
5Built-up area= 107.00 m²
6Area taken by walls= 9.00 m²
7Carpet to super built-up ratio= 1.4861

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 or compounding frequency into account.
Figures are rounded for display to 4 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

How is the Built Up Area figure worked out?

Built-up = carpet x (1 + wall allowance) + balcony. Carpet area is the usable floor inside the walls.

Which area should a price be compared on?

Carpet area, because it is the only one with a consistent definition. A quoted rate per square foot on super built-up area can hide a loading factor anywhere from 15 to 50 percent.

What values do I need to enter?

This calculator takes 4 inputs: Carpet area, Wall and duct allowance, Balcony and terrace area, Common area loading. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.