Estimate how many gallons of paint, sealant, or liquid are needed per square foot of surface area.
About Gallons per Square Foot Calculation
The Gallons per Square Foot Calculator helps estimate liquid usage for coating, sealing, or irrigating
surfaces. It uses surface area, number of coats, and coverage rate to calculate total gallons and cost.
The main formula is straightforward:
Gallons per ft² = Total Gallons ÷ Total Area
Total Gallons = Area × Coverage Rate × Number of Coats × (1 + Waste%)
Key Considerations
- Surface Area: Accurately measure the total area to be covered in square feet.
- Coverage Rate: Check product labels (e.g., paint typically covers 350–400 ft²/gallon).
- Number of Coats: Multiply total gallons for each layer or coat applied.
- Waste Allowance: Add 5–10% for losses due to texture, overspray, or spillage.
- Cost Estimation: Enter the price per gallon to compute total expenditure.
- Conversions: 1 U.S. Gallon = 3.785 Liters; 1 ft² = 0.0929 m².
Typical Coverage Rates (for reference)
- Paint — 0.0025 gal/ft²
- Sealant — 0.0040 gal/ft²
- Epoxy — 0.0060 gal/ft²
- Water (1/16") — 0.0104 gal/ft²
- Thick Coating — 0.0120 gal/ft²
- Primer — 0.0030 gal/ft²