Paint Coverage Calculator
Calculate how much paint you'll need for your project based on surface area and coverage rate.
Need help calculating wall area?
Paint Requirement Results
Surface Area:
Paint Needed:
Paint Cans:
Calculation:
About Our Paint Coverage Calculator
Our Paint Coverage Calculator is an essential tool for homeowners, contractors, and DIY enthusiasts planning painting projects. This calculator helps you determine exactly how much paint you'll need, saving you both time and money by preventing unnecessary trips to the store or wastage from buying too much.
How to Calculate Paint Requirements
Determining how much paint you need requires understanding the relationship between surface area and paint coverage rate. Our calculator uses the following formula:
Paint Required = (Surface Area × Number of Coats) ÷ Coverage Rate
Where:
- Surface Area is the total area to be painted (in square feet or square meters)
- Number of Coats is how many layers of paint you plan to apply
- Coverage Rate is how much area one gallon or liter of paint will cover (typically found on the paint can label)
Key Features:
- Calculate paint needs in both imperial (ft², gallons) and metric (m², liters) units
- Account for multiple coats of paint
- Built-in room dimension calculator for easy wall area estimation
- Option to exclude doors, windows, and other non-painted areas
- Recommendations for standard paint can sizes to purchase
Tips for Accurate Calculations:
- Check the Coverage Rate: Different paint types and brands have different coverage rates. The standard is around 350-400 ft² per gallon (or 8-10 m² per liter) for most interior paints.
- Consider the Surface: Textured, porous, or dark-colored surfaces may require more paint. For these surfaces, use the lower end of the coverage rate range.
- Add Extra for Touch-ups: Consider adding 10% extra for touch-ups or errors, especially for large projects.
- Don't Forget the Primer: If your project requires primer, calculate that separately using the same method.
Common Paint Container Sizes:
Imperial (US):
- Sample/Quarter Pint: 1/16 gallon (0.0625 gal)
- Half Pint: 1/8 gallon (0.125 gal)
- Pint: 1/8 gallon (0.125 gal)
- Quart: 1/4 gallon (0.25 gal)
- Half Gallon: 0.5 gallon
- Gallon: 1 gallon (most common)
- 5-Gallon Bucket: 5 gallons
Metric:
- Sample Size: 75-100 ml
- Small Can: 250 ml
- Medium Can: 500 ml
- Standard Can: 1 liter
- Large Can: 2.5 liters
- Bucket: 5 liters
- Large Bucket: 10 liters
Whether you're painting a single wall or an entire house, our Paint Coverage Calculator will help you purchase just the right amount of paint for your project, saving you money and reducing waste.
Frequently Asked Questions
How do I know what paint coverage rate to use?
Look at the paint can or manufacturer's specifications for the most accurate coverage rate. If that information isn't available, you can use these general guidelines: for smooth, primed surfaces, use 350-400 square feet per gallon; for textured or unprimed surfaces, use 300-350 square feet per gallon; for rough, porous surfaces, use 250-300 square feet per gallon. For metric measurements, typical values range from 8-10 square meters per liter for smooth surfaces.
Should I always plan for two coats of paint?
In most cases, yes. Two coats generally provide better coverage, color consistency, and durability. One coat might be sufficient when:
- You're painting the same color or a very similar shade
- Using premium paints specifically designed for one-coat coverage
- The surface has been properly primed with a tinted primer
How do I calculate paint for irregularly shaped rooms?
For irregularly shaped rooms, break down the space into simple geometric shapes (rectangles, squares, triangles). Calculate the area of each surface separately, then add them together. For curved walls, you can approximate them as straight sections. Remember to subtract the area of windows, doors, and other items you won't be painting. Our calculator helps with rectangular rooms, but for complex spaces, you might need to do some additional measurements and add the results to the "Total Surface Area" field.