How Many Gallons to Paint Exterior House: My Real Calculation Guide: 1 Minute to Estimate Painting Needs and Avoid Running OutSarah ThompsonSep 05, 2025Table of ContentsEstimate Gallons for Painting Exterior HouseTips 1: Paint Type, Climate & CoverageFAQTable of ContentsEstimate Gallons for Painting Exterior HouseTips 1 Paint Type, Climate & CoverageFAQFree Smart Home PlannerAI-Powered smart home design software 2025Home Design for FreeWondering how many gallons to paint exterior house efficiently? If your last attempt involved endless trips back to the store, you’re not alone—I’ve been there. Accurately estimating paint will save you time and frustration, and your home exterior deserves that pro finish from the start. The quick answer: Most standard homes require between 10–20 gallons, but let's break it down with a proven formula and my own experience.When I first moved into my compact craftsman, I used a free floor plan creator to measure the surface area precisely. Surface area is key—count every wall and subtract windows and doors for precision. Typically, a gallon covers 350–400 square feet, and wilder surfaces like stucco eat up more paint. For reference, my 1,600 sq ft bungalow with lots of trim and porches ended up taking 15 gallons over two coats. If your house has lots of architectural features, don't forget to plan where trim and accent colors will go before buying.Estimate Gallons for Painting Exterior HouseFirst, measure each wall’s height and width. Multiply these numbers to get square footage. Subtract non-painted areas—windows, doors, and large vents. I found it helpful to use digital tools for quick tallying. For homes with smooth siding, stick to 1 gallon per 350–400 sq ft. Older homes or textured walls (like mine) may need extra for thick applications. Always add 10% for touch-ups and errors. Years ago, running short meant my touch-up section looked like a patchwork!Tips 1: Paint Type, Climate & CoverageYour climate changes the rules. In humid zones, paint may go further—while super dry deserts require thicker coats for the same coverage. Choose quality exterior paint for longer durability. I always run numbers twice and simulate color choices using AI home design tools for visual confirmation. Bonus tip: If you’re painting brick, up the estimate—porous materials can absorb up to 25% more paint than smooth siding.FAQHow do I calculate my exterior paint needs?Multiply wall height by width for square footage, subtract non-paintable areas, and divide by the coverage per gallon (usually 350–400 sq ft).Does texture affect how many gallons I need?Yes. Stucco, brick, or rough siding require up to 25% more than smooth surfaces.How many coats should I plan for?Most exteriors need 2 coats; touch-ups may require extra.What if I run out halfway through?Add 10% more paint to your initial estimate to cover mishaps and touch-ups.Home Design for FreePlease check with customer service before testing new feature.