Square Inches to Square Feet Calculator
Convert between square inches and square feet. 1 sq ft = 144 sq in (because 12 in × 12 in = 144 sq in). Common for tile, fabric, and small-area projects.
Inches ⇌ Feet Converter
The conversion math
1 ft = 12 in. So 1 sq ft = 12 × 12 = 144 sq in. To convert sq in → sq ft, divide by 144. To convert sq ft → sq in, multiply by 144.
For dimensions in inches: convert inches to feet (divide by 12) BEFORE multiplying. A 30 in × 24 in tile = 2.5 ft × 2 ft = 5 sq ft, NOT 720 sq ft (which would be 30 × 24).
When to work in inches
Tile dimensions are usually given in inches (12×12, 18×18, 24×24). Convert each dimension to feet, then multiply for square footage per tile.
Fabric, paper, and small-format projects often use inches throughout. For these, calculate in square inches first, then divide by 144 only at the very end.
Converting between inches, feet, and square feet
Mixing inches and feet is the #1 source of square footage errors. The conversions:
Inches to decimal feet: divide by 12. 6 in = 0.5 ft. 9 in = 0.75 ft. 3 in = 0.25 ft.
Feet plus inches to decimal feet: ft + (in ÷ 12). 10 ft 6 in = 10.5 ft. 8 ft 3 in = 8.25 ft.
Square inches to square feet: divide by 144 (since 1 sq ft = 12 × 12 = 144 sq in). 288 sq in = 2 sq ft. 720 sq in = 5 sq ft.
Worked example: a room measures 10 ft 6 in × 8 ft 3 in. Decimal: 10.5 × 8.25 = 86.625 sq ft. Skipping the inches conversion (just 10 × 8 = 80 sq ft) underestimates by 7%.
Common inch-to-foot conversions
Quick reference: 1 in = 0.083 ft. 2 in = 0.167 ft. 3 in = 0.25 ft. 4 in = 0.333 ft. 5 in = 0.417 ft. 6 in = 0.5 ft. 7 in = 0.583 ft. 8 in = 0.667 ft. 9 in = 0.75 ft. 10 in = 0.833 ft. 11 in = 0.917 ft.
Square inches to square feet: divide by 144. 144 sq in = 1 sq ft. 288 = 2 sq ft. 576 = 4 sq ft. 1,440 = 10 sq ft. 14,400 = 100 sq ft.
Common applications: 12 × 12 in tile = 144 sq in = 1 sq ft. 6 × 6 in tile = 0.25 sq ft. 24 × 24 in tile = 4 sq ft. 3 × 6 in subway tile = 0.125 sq ft (8 tiles per sq ft). 4 × 8 ft sheet (drywall, plywood) = 32 sq ft.
When precision matters
Use exact inches (1/8 inch precision): cabinet installation, countertop fabrication, tile layout, herringbone flooring.
Round to the nearest inch: flooring orders, paint estimates, carpet, drywall, paneling.
Round to the nearest foot: rough estimates, ballpark budgeting, comparing room sizes.
For material orders: use measurements at the highest accuracy you have, then apply waste factor. Don't pre-round before waste — rounding compounds errors. A 10 ft 8 in × 9 ft 4 in room is 99.55 sq ft exact, but rounded to 10 × 9 ft is only 90 sq ft (10% short). Always start with exact measurements.
Pro tips
Consistent units always
Don't mix feet and inches in the same multiplication. Convert everything to one unit (usually feet) before calculating.
Use feet+inches input
The calculator above has a feet+inches input field that handles the conversion automatically. 12 ft 6 in becomes 12.5 ft.
Tile counts come from sq ft
Tile is sold by the box (covering X sq ft). Calculate your floor in sq ft, divide by sq ft per box, round up. Don't calculate in sq in - boxes are listed in sq ft.
Decimal feet for accuracy
1 inch = 0.0833 feet. 6 inches = 0.5 ft. 9 inches = 0.75 ft. Memorize these or use the feet+inches input field.