# Paint Calculator Use our free paint calculator to estimate how much paint you need for any room. Shows coverage, cost, and number of gallons required. --- - **Canonical URL:** https://dothecalculation.com/calculators/paint-calculator - **Category:** Everyday utilities - **Publisher:** Do The Calculation (https://dothecalculation.com) - **Cost:** Free, no account or sign-up required - **Privacy:** Runs entirely in the browser; inputs are never sent to a server - **Methodology:** https://dothecalculation.com/methodology --- ## Frequently asked questions ### What is a paint calculator? A paint calculator is a tool that helps you estimate how much paint you'll need for a room or building by analyzing room dimensions, doors, windows, coats, and texture absorption rates. ### How much paint do I need for a 12×12 room? For a standard 12 ft × 12 ft × 8 ft room (approx. 384 sq ft of walls), you'll need about 1 gallon for 1 coat or 2 gallons for 2 coats (rounded up from 1.75). ### How much does a gallon of paint cover? A standard gallon covers about 350 to 400 square feet of smooth drywall. Textured, rough, or porous surfaces reduce coverage to 250-300 sq ft per gallon. ### How many coats of paint do I need? Most interior projects require 2 coats. A refresh of the exact same color may need 1 coat, while dramatic dark-to-light changes may require 3 coats. ### How much paint do I need for exterior painting? Exterior painting typically needs 2 coats. Exterior surfaces are more porous (wood, brick, stucco), so add a 15-20% coverage buffer to prevent running short. ### Do I need primer before painting? Primer is highly recommended for bare drywall, new wood, stained areas, or when making a drastic color change (e.g. dark navy to white). It seals the surface so your topcoat adheres uniformly. ### How do I measure an irregular room? Break the room layout down into smaller rectangular sections, calculate the wall areas for each section, and sum them. Or add them as separate rooms in our calculator! ### How much does it cost to paint a room? DIY painting materials and supplies cost between $50 and $200 per room. Hiring a professional painter averages $300 to $800 per room depending on labor rates. ## Related guides - [Paint Calculator: A Complete Guide to Calculate Paint Quantity, Coverage & Cost](https://dothecalculation.com/blog/utility/paint-calculator-quantity-coverage-cost-guide) — Learn the paint calculation formula step by step, how to measure wall area with door and window deductions, coverage rates by paint type, coats needed, and paint cost — with practice problems. - [How to Calculate Paint Quantities: Room Measurement & Gallons Guide](https://dothecalculation.com/blog/utility/how-to-calculate-paint-quantities) — The exact steps to measure any room — rectangular or irregular — and turn those measurements into gallons of paint, with 4 fully worked multi-room examples and a square feet ↔ square meters conversion table. - [Concrete Volume Guide: Slab Yardage, Waste Allowance, and Bag Estimates](https://dothecalculation.com/blog/utility/concrete-volume-estimation) — Learn how to calculate concrete volume for slabs and footings. Convert length, width, and depth into cubic yards and 80 lb bags, and apply the correct waste allowance before ordering. ## Related calculators - [Square Footage Calculator](https://dothecalculation.com/calculators/square-footage-calculator) — Calculate area square footage for complex composite room shapes and estimate material counts instantly and accurately for free. - [Emergency Fund Calculator](https://dothecalculation.com/calculators/emergency-fund-calculator) — Estimate how much emergency savings you need based on monthly expenses to cover unexpected income loss or urgent expenses. - [Bill Split Calculator](https://dothecalculation.com/calculators/bill-split-calculator) — Split a bill evenly or by share among any number of people, including tip percentage and service charges, instantly for free. - [Concrete Calculator](https://dothecalculation.com/calculators/concrete-calculator) — Estimate concrete volume, bag counts, and material costs for slabs, footings, and other construction projects instantly for free. - [Day of the Year & Julian Date Calculator](https://dothecalculation.com/calculators/day-of-year-calculator) — Find the ordinal day number for any calendar date, compute Julian Date (JD), calculate remaining days in the year, and check if it is a leap year. - [GPA Cumulative Target Grade Requirement Calculator](https://dothecalculation.com/calculators/gpa-cumulative-target-calculator) — Find the required GPA in your remaining credits needed to achieve a target cumulative GPA instantly with this free online tool. --- _Source: [Do The Calculation](https://dothecalculation.com/calculators/paint-calculator). Quote freely with attribution and a link to this page._