Square Footage Calculator

Manual

Use the calculator to total one or more simple areas while keeping the dimensions and unit choices visible.

Add and remove areas

The calculator starts with one rectangle. Use Add area for another room or shape. Each row can have an optional name and a quantity for repeated identical areas. B01 supports up to 100 active rows.

Choose a shape

Rectangle uses length and width. Square uses one side. Triangle uses a base and the perpendicular height. Circle uses diameter. Known area accepts an area value that is already measured.

Mix measurement units

Each geometric dimension can use inches, feet, yards, millimeters, centimeters, or meters. Known areas can use square inches, square feet, square yards, square millimeters, square centimeters, square meters, or acres.

Calculate and read the breakdown

Select Calculate after entering valid areas. The headline result is total square footage. Square yards, square meters, acres, and the per-area breakdown come from the same unrounded result model.

Changing an input

Changing any area after a calculation makes the old result stale. Copy, CSV, and Print / Save PDF stay disabled until you calculate again.

Copy, CSV, and Print / Save PDF

Copy result creates a compact text summary. Download CSV keeps the area rows and totals. Print / Save PDF uses the current page so the visible inputs, totals, and breakdown can be kept as a printable record.

Validation

Dimensions and known areas must be positive plain decimal numbers. Quantity must be a whole number from 1 through 1,000,000. Commas, exponent notation, zero dimensions, and unsupported unit values are rejected.