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Paint Calculator

Calculate paint required for walls, rooms, and projects

Room/Wall Dimensions
Wall 1
ft
ft
Wall 2
ft
ft
sq ft
Total area of doors, windows, and other non-paintable surfaces
Paint Specifications
sq ft/gal
Area covered per gallon/liter
coats
/gal
Paint Calculation Results
$125.50
Total Paint Cost
Total Paintable Area: 240 sq ft
Paint Required: 1.37 gallons
Paint Cans Needed: 2 cans (1 gal each)
Paint Type: Latex Paint
TOTAL COST: $125.50
Paint Waste Factor: 10%
0% 5% 10% 15% 20%
Shopping List
1
Latex Paint - 1 Gallon
Covers approx. 350 sq ft
$25.00
2
Latex Paint - 1 Gallon
Covers approx. 350 sq ft
$25.00
Quick Tips
  • Measure twice, paint once! Double-check your dimensions
  • Add 10-15% extra paint for waste and touch-ups
  • Different surfaces may require different paint types
  • Primer is recommended for new or unpainted surfaces
All Calculators
Tip

Use the search bar above to quickly find the calculator you need.

Measurement Guide

1 gallon covers 350-400 sq ft. Add 10% extra for waste. Primer may be needed for new walls.

How to Use
  1. Enter wall dimensions (height & width)
  2. Subtract doors/windows area
  3. Select paint type & coats
  4. Get accurate paint requirements
Coverage Rates
  • Latex Paint: 350-400 sq ft/gal
  • Oil-Based: 300-350 sq ft/gal
  • Emulsion: 400-450 sq ft/gal
  • Primer: 200-300 sq ft/gal
Important Notes
  • Rough surfaces need more paint
  • Dark colors may require extra coats
  • Always buy from same batch for color consistency
  • Consider primer for new drywall

About This Paint Calculator

Estimating the right amount of paint is essential for saving money and avoiding shortages during a project. This advanced Paint Calculator helps homeowners, contractors, and interior designers accurately determine how much paint is required based on wall dimensions, number of coats, coverage rate, and waste factor.

Instead of guessing how many gallons you need, the calculator computes total paintable area, subtracts doors and windows, applies multiple coat calculations, and recommends the exact number of paint cans required.

The tool supports multiple measurement units including feet, meters, and centimeters, making it suitable for global users. It also provides a detailed shopping list and total project cost to help you plan your budget efficiently.

How the Paint Calculator Works

1. Wall Area Calculation

The calculator multiplies wall height by width for each wall and sums all areas to determine total surface area.

2. Subtract Non-Paint Areas

Doors, windows, and other non-paintable sections are subtracted from the total wall area to ensure accurate paint estimation.

3. Apply Number of Coats

The total paintable area is multiplied by the number of coats selected to calculate total surface coverage required.

4. Paint Coverage Formula

Required Paint Volume = (Total Paintable Area × Coats) ÷ Coverage Rate.

5. Waste Factor & Cost Calculation

A waste percentage is added to account for spills and touch-ups. The calculator then multiplies required paint cans by price per unit to estimate total cost.

Frequently Asked Questions

How much paint do I need for one room?
It depends on wall dimensions and number of coats. On average, one gallon covers about 350–400 square feet for one coat.
Should I include ceiling in calculation?
If you plan to paint the ceiling, measure its area and include it as an additional wall section.
Why add extra paint for waste?
Adding 10–15% extra ensures you have enough paint for touch-ups and uneven surfaces.
Does paint type affect coverage?
Yes. Different paint types such as latex, oil-based, and premium paints have varying coverage rates.