Calculate exactly how much paint you need for any project. Multi-room support, 12+ paint types, automatic deductions for doors and windows, cost estimation, and professional-grade accuracy trusted by contractors worldwide.
Interior Eggshell
Slight sheen, ideal for living rooms and bedrooms. Easy to clean.
21 sq ft each
15 sq ft each
Whether you're a professional contractor, interior designer, or DIY homeowner, accurately calculating paint quantities is essential for any successful painting project. Our professional Paint Calculator eliminates guesswork by providing precise estimates based on room dimensions, paint type, coverage rates, and the number of coats needed. This comprehensive tool supports both imperial (feet, gallons) and metric (meters, liters) measurements, making it ideal for projects worldwide.
Calculating paint requirements involves measuring your room dimensions and applying a simple formula. The basic calculation is: Total Wall Area = 2 × (Length + Width) × Height. From this total, subtract the area of doors (approximately 21 square feet each) and windows (approximately 15 square feet each). The remaining area is your paintable surface. Divide this by the paint coverage rate (typically 350-400 sq ft per gallon) and multiply by the number of coats to get the total gallons needed.
Paint coverage varies significantly based on several factors. Premium quality paints typically cover 350-400 square feet per gallon on smooth, properly prepared surfaces. However, coverage can decrease to 250-300 square feet on textured, porous, or unpainted surfaces. Flat and matte finishes generally provide better coverage than glossy finishes due to their thicker, more absorbent nature. Our calculator includes 12 different paint types with accurate coverage rates for each.
Most professional painters recommend applying two coats of paint for optimal coverage, durability, and color depth. A single coat may be sufficient for touch-ups or when painting over a similar color. However, when making dramatic color changes—especially from dark to light—you may need three or four coats. Using a tinted primer as your first coat can reduce the number of topcoats needed and save both time and money.
Selecting the right paint type is crucial for achieving professional results:
Paint prices range from $15-25 per gallon for budget options to $50-80+ for premium brands. While expensive paint costs more upfront, it often provides better coverage, requiring fewer coats and less total paint. Our calculator helps you budget accurately by estimating total costs based on your specific paint price and project requirements. Remember to factor in additional supplies: brushes ($5-20), rollers ($5-15), tape ($5-10), and drop cloths ($10-30).
For larger projects involving multiple rooms or entire houses, our calculator's multi-room feature is invaluable. Add each room separately with its unique dimensions, then get a consolidated total for all surfaces. This approach helps you purchase paint efficiently—buying in larger quantities often provides significant discounts. For whole-house projects, consider using the same paint color throughout hallways and connected spaces to create visual flow and simplify purchasing.
Different surfaces require specific approaches. Ceilings typically need only one coat of specialized ceiling paint, which is formulated to resist drips and spatter. Trim and baseboards require semi-gloss or high-gloss paint for durability and easy cleaning. Kitchens and bathrooms benefit from mildew-resistant formulations. Exterior surfaces require weather-resistant paint rated for UV exposure and temperature fluctuations. Our calculator accommodates all these variations with customizable coverage rates and surface types.
A professional paint calculator offers numerous advantages over manual estimation. It eliminates mathematical errors, accounts for all variables (doors, windows, multiple coats), provides instant cost estimates, and ensures you purchase the right amount of paint—avoiding both shortages and expensive waste. Our calculator also maintains a history of your calculations, making it easy to reference past projects or plan future ones. For contractors, the export feature creates professional documentation for client proposals.
“As a painting contractor, accurate estimates are crucial for profitable jobs. This calculator accounts for every variable - doors, windows, coats, coverage rates. The multi-room feature saves me hours on large projects. Best paint calculator I've used in 15 years.”
“I recommend this tool to all my clients. The room presets and paint type recommendations are spot-on. Being able to export detailed reports makes it easy to share specifications with contractors. Incredibly professional and accurate.”
“Painted my entire house using this calculator - 8 rooms, 2 bathrooms, and all the trim. The estimate was within one gallon of what I actually used. The cost breakdown helped me budget perfectly. Saved me multiple trips to the hardware store!”
“Managing 50+ rental units means constant repainting. This calculator helps me estimate paint needs and costs for tenant turnovers. The history feature lets me track calculations for different properties. Indispensable tool for my business.”
“When flipping houses, accurate paint estimates directly impact profits. This calculator considers everything - surface type, coverage rates, multiple coats. The metric/imperial toggle is perfect for my international properties. Highly recommended!”
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