House Square Footage Calculator
A house total is just a list of rooms added honestly. The rows below start with a typical layout — rename them, change the numbers, delete rows and add your own until the list matches the house you're measuring.
| Areas added | — |
| Cut-outs subtracted | — |
| Net area | — |
| In square yards | — |
| In square meters | — |
| In acres | — |
| Area incl. waste | — |
| Estimated material cost | — |
Everything is calculated locally in your browser — no measurements are sent anywhere. Mixed units are converted exactly (1 ft = 0.3048 m, 1 sq yd = 9 sq ft, 1 acre = 43,560 sq ft).
The preset rooms total 626 sq ft (192 + 120 + 132 + 100 + 40 + 42). Waste is set to 0 here because a house total is an area figure, not a material order — turn it up if you are pricing flooring for the whole floor.
What counts toward living area — and what doesn't
There are two different numbers people call "house square footage", and mixing them up causes most arguments between listings:
| Space | Physical area | Usually in living area (GLA) |
|---|---|---|
| Bedrooms, living rooms, kitchens, baths | Yes | Yes |
| Finished, heated attic with ≥ 7 ft ceilings | Yes | Usually yes |
| Finished basement | Yes | Usually reported separately (below grade) |
| Garage, even converted-looking | Yes | No, unless fully converted & permitted |
| Porches, decks, patios | Yes | No |
| Unfinished rooms, storage sheds | Yes | No |
Appraisers in the US follow the ANSI Z765 standard for gross living area (GLA): finished, above-grade space, heated and with adequate ceiling height, measured from the exterior walls. This calculator measures interior room dimensions, so your total will typically come out a little lower than an appraisal figure — wall thickness is the difference. Use this number for materials, comparisons and planning; use a licensed appraiser's number for a sale or a loan.
Tips for a whole-house measure
Work floor by floor. Finish one level, check the subtotal against the floor's outside dimensions (length × width of the footprint is an upper bound your rooms cannot exceed).
Don't forget the in-between spaces. Hallways, landings and closets are the classic misses — together they're often 8–12% of a house.
Stairs count once. The stair opening belongs to the floor it serves; don't measure the staircase as its own room on both levels.
Pricing work on a house this size?
Contractors: turn measurements into a bid with ProfitBid — priced quotes with your margin built in — and cross-check the budget on RemodelCostCalc.
House questions
Why is my total lower than the listing said?
Listings usually quote GLA from exterior measurements, which include wall thickness, and sometimes include finished below-grade space. A room-by-room interior measure like this one is the honest physical area — expect it to run 5–10% below the listing figure on the same house.
Should I measure every room or use the outside dimensions?
Outside dimensions (footprint × floors) are a fast estimate but overstate the livable area and are useless for buying materials. Room by room takes twenty minutes longer and gives you numbers you can actually order against.
Does a two-story house just double the footprint?
Only if both floors are identical in outline and fully finished. Measure each floor's rooms separately — upstairs rooms over a garage or porch often differ from the rooms below.