Square Footage Calculator
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Calculating Total Square Footage for Any Home or Space
Square footage is the most commonly referenced number in real estate, construction, and home renovation — and one of the most commonly miscalculated. Whether you're getting flooring quotes, listing a property, planning a renovation budget, or verifying a home's listed footage, getting an accurate total requires measuring every room and knowing which spaces count.
How to Use This Calculator
Enter the length and width of up to 6 rooms or areas, give each a name, and select your unit system (feet, meters, or yards). Hit Calculate Total to see the combined area in all three unit systems, room count, and average room size. The donut chart shows each room as a proportion of the total.
Square Footage Formula
Total home square footage = sum of all rooms including hallways, closets, and staircases if they're finished space. A living room 18 × 15 ft = 270 sq ft. Kitchen 12 × 12 ft = 144 sq ft. Two bedrooms 14 × 12 ft = 168 sq ft each. Running total: 270 + 144 + 168 + 168 = 750 sq ft for those four spaces.
What Counts Toward Square Footage?
- Included: All finished, heated, above-grade living space — bedrooms, living rooms, kitchens, bathrooms, hallways, closets, staircases
- Usually excluded: Unfinished basements, garages, attics (unless finished and conditioned), screened porches, decks
- Varies: Finished basements are often listed separately as "below-grade finished area," not added to the main figure
When verifying real estate listings, confirm what's included. ANSI Z765 is the standard for residential square footage measurement, but agents don't always follow it consistently.
Average Home and Room Sizes (US)
- New single-family home: ~2,200 sq ft (US average, 2023)
- New apartment: ~950 sq ft
- Living room: 250–400 sq ft
- Master bedroom: 200–300 sq ft
- Secondary bedroom: 120–200 sq ft
- Kitchen: 100–200 sq ft
- Full bathroom: 40–100 sq ft
Frequently Asked Questions
How do I measure square footage for a home listing?
Measure each finished, above-grade room using a tape measure or laser distance meter — measure to the inside of exterior walls. For irregular shapes, break rooms into rectangles and sum the areas. Measure hallways and closets too. Document your measurements — buyers and appraisers may verify them, and discrepancies can create negotiation issues or legal complications in some states.
Does square footage include the garage?
In most residential listings, garages are not included in living square footage because they're unheated, unfinished, and not habitable space. They're typically listed separately. An attached garage that has been finished and conditioned may be counted — but this should be disclosed and may not be counted the same way by appraisers. Always clarify with the listing agent exactly what's included in any stated figure.
How accurate do I need to be for flooring estimates?
Within 5% is sufficient for flooring quotes. Measure in feet, include closets, and always order 10% extra for waste (15% for diagonal patterns). Make sure all boxes come from the same production lot. Flooring contractors typically measure in person before ordering — use this calculator to cross-check their estimates and catch significant discrepancies before you sign a contract.
What's the difference between gross and net square footage?
Gross square footage measures from the outside of exterior walls. Net square footage measures the interior floor space. For single-family homes, the difference is wall thickness — typically 6–8% smaller for net vs. gross. In commercial real estate, the difference is much larger because it accounts for shared corridors, lobbies, restrooms, and mechanical rooms that tenants may or may not be paying for.
How do I convert square feet to square meters?
1 sq ft = 0.0929 sq m. To convert sq ft to sq m: divide by 10.764. To convert sq m to sq ft: multiply by 10.764. A 2,000 sq ft home = 185.8 sq m. This conversion is needed when comparing US home listings to properties in Canada, Europe, Australia, or anywhere that uses square meters as the standard unit for floor area.