Square Footage Calculator
Enter the length and width of each room to calculate area in square feet and square meters. Add as many rooms as needed. Total square footage updates as you type.
A. Room Square Footage
| Room Name | Length | Width | Unit | Area | |
|---|---|---|---|---|---|
| 300.0 sq ft 27.9 sq m | |||||
| 168.0 sq ft 15.6 sq m | |||||
| 120.0 sq ft 11.1 sq m |
B. Quick Area Conversion
How to Calculate Square Footage
Square footage is the most common unit for measuring floor area in the United States. Whether you are buying flooring, comparing homes, estimating paint, planning a tile job, or calculating how much carpet to order, square footage is the starting point.
Basic Formula
Square Footage = Length (ft) × Width (ft)
For a room that is 14 feet long and 11 feet wide:
14 ft × 11 ft = 154 sq ft
Measuring Irregular Rooms
L-shaped rooms, rooms with alcoves, and open-plan spaces with offsets require dividing the floor plan into simple rectangles, measuring each separately, and summing the results.
L-shaped living room example: Main area : 20 ft × 15 ft = 300 sq ft Dining nook : 12 ft × 10 ft = 120 sq ft ──────────────────────────────────────── Total : 420 sq ft
For curved walls or unusual shapes, you can approximate by dividing into rectangles and triangles. The area of a right triangle is (base × height) / 2.
Square Feet to Square Meters Conversion
The international standard unit for area is the square meter. The conversion factors are:
| Square Feet | Square Meters |
|---|---|
| 1 sq ft | 0.0929 sq m |
| 100 sq ft | 9.29 sq m |
| 500 sq ft | 46.45 sq m |
| 1,000 sq ft | 92.90 sq m |
| 1,500 sq ft | 139.35 sq m |
| 2,000 sq ft | 185.81 sq m |
| 2,500 sq ft | 232.26 sq m |
Square Footage for Common Projects
Flooring: Measure each room, add 5–10% for waste and cuts, and check how many square feet each box covers. Different products cover different amounts per box; the label always states coverage.
Paint: One gallon of interior paint covers approximately 350–400 square feet of wall area for one coat. To calculate wall area, measure the perimeter of the room and multiply by ceiling height, then subtract for doors and windows (each typically about 21 sq ft for a standard door and 15 sq ft for a standard window).
Carpet: Carpet is sold by the square yard (1 sq yd = 9 sq ft). Divide your square footage by 9 to get square yards. Add 10–15% waste, especially for rooms that are not square because carpet must be cut to fit and seamed.
Tile: Add 10% for straight-lay and 15–20% for diagonal-lay installations. Buy all tiles from the same production batch (dye lot) to ensure color consistency; it is difficult to match exactly if you run short later.
Acreage and Larger Areas
For larger properties, land is typically measured in acres. One acre = 43,560 square feet. A square acre would be about 208.7 feet on each side. Common acreage equivalents:
| Square Feet | Acres |
|---|---|
| 43,560 sq ft | 1.000 acre |
| 21,780 sq ft | 0.500 acre (half acre) |
| 10,890 sq ft | 0.250 acre (quarter acre) |
| 6,534 sq ft | 0.150 acre |
| 4,356 sq ft | 0.100 acre |
Frequently Asked Questions
How do I calculate the square footage of a room?
Measure the length and width of the room in feet, then multiply them. Length × Width = Square Footage. For a 15 ft × 12 ft bedroom: 15 × 12 = 180 sq ft. For L-shaped or irregular rooms, divide the space into rectangles, calculate each one separately, and add the results together.
How many square feet are in a square meter?
One square meter equals approximately 10.7639 square feet. To convert square feet to square meters, divide by 10.7639. To convert square meters to square feet, multiply by 10.7639. For example, 500 sq ft ÷ 10.7639 = 46.45 sq m.
How much does square footage affect home value?
Price per square foot ($/sqft) varies enormously by location, condition, and amenities. In the US, median price per square foot ranged from roughly $100–$150/sqft in rural Midwest markets to $600–$1,000+/sqft in San Francisco and Manhattan as of 2024–2025. Real estate appraisals use comparable sales (comps) of similar square footage in the same area to estimate value. Finished above-grade living space is counted differently from unfinished basements and garages.
Does square footage include the garage and basement?
Typically, finished above-grade living space is counted as gross living area (GLA) for real estate purposes. Attached garages are excluded from GLA even if finished. Finished basements are treated inconsistently — many appraisers exclude them from GLA but note them separately. An unfinished basement is never counted as GLA. For renovation projects, you may want to measure the actual floor area regardless of how it is classified for real estate.
How do I calculate square footage for flooring or tile?
Measure the total floor area you need to cover and add a waste allowance. For straight-lay tile or planks, add 5–10% waste. For diagonal tile installations, add 10–15%. For unusually shaped rooms, add up to 20%. Divide your total (including waste) by the coverage per box to find the number of boxes. For example, 250 sq ft × 1.10 (10% waste) = 275 sq ft; if each box covers 20 sq ft, you need 275 ÷ 20 = 13.75, rounded up to 14 boxes.
Related Calculators
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- Electricity Cost Calculator — monthly appliance energy cost by wattage and usage
- Area Converter — convert between sq ft, sq m, sq yd, acres, and hectares