Square Footage Calculator
Calculate precise square footage for rectangles, circles, triangles, and L-shapes. Convert project dimensions into material order quantities and cost estimates.
Job-site cuts, irregular contours, compaction, and spillage typically require 5–15% extra material.
Estimate & BOQ Generator
Turn calculated quantities into an itemized customer bid with overhead and profit markup.
How to Calculate Square Footage
Square footage is the measurement of area inside a two-dimensional geometric plane. In construction and home improvement, knowing exact square footage is critical for ordering flooring boxes, tile, carpet, sod, paint, and drywall without costly over-purchasing or mid-job shortages.
Square Footage Formulas by Shape
Area = Length (ft) × Width (ft)Area = 0.5 × Base (ft) × Height (ft)Area = π × Radius (ft)²Area = 0.5 × (Base A + Base B) × HeightMaterial Coverage Benchmarks
| Material | Standard Packaging | Coverage per Unit | Recommended Waste |
|---|---|---|---|
| Hardwood / Laminate | 1 Box | 20–24 sq ft | 10% |
| Ceramic / Porcelain Tile | 1 Box (12"×12" or 12"×24") | 10–15 sq ft | 15% |
| Interior Wall Paint | 1 Gallon Can | 350–400 sq ft (1 coat) | 10% |
| Lawn Sod Rolls | 1 Roll (2' × 5') | 10 sq ft | 5–10% |
| Lawn Sod Pallet | 1 Pallet (45–50 rolls) | 450–500 sq ft | 5% |
Frequently Asked Questions
How do you calculate square footage of an irregular room?▼
For irregular L-shaped or multi-section rooms, divide the floor plan into individual rectangles or squares. Calculate the area of each section (Length × Width) and add them together. Then add 10% to account for cutting waste.
How much waste should I add for flooring and tile?▼
For standard square or rectangular rooms with laminate or vinyl plank flooring, add 10% waste. For diagonal tile layouts, herringbone patterns, or rooms with many closets/angles, add 15% to 20% waste.
How many square feet does one gallon of paint cover?▼
One standard gallon of interior paint covers approximately 350 to 400 square feet with one coat. For new drywall or dramatic color changes, two coats are recommended (approx. 175–200 sq ft per gallon total).
How do you calculate square footage for sod?▼
Calculate your lawn area in square feet. A standard roll of sod covers 10 square feet (2 ft × 5 ft), while a full pallet of sod typically covers 450 to 500 square feet (45–50 rolls).
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