How Far Does a Gallon of Paint Go?
Paint coverage — also called spread rate — is the area one gallon of paint covers at the correct film thickness. Most interior latex paints claim 400 square feet per gallon on the label. In practice, real-world coverage is typically 350 to 380 square feet per gallon on smooth walls due to surface texture, roller absorption, and lap allowances.
Coverage varies significantly by surface type. Smooth drywall achieves the label rate of 400 square feet per gallon. Orange peel textured walls achieve 300 to 350 square feet per gallon. Heavy knockdown texture achieves 250 to 300 square feet per gallon. Rough masonry, brick, and stucco achieve 150 to 200 square feet per gallon due to deep penetration into the porous surface.
The number of coats also affects how you calculate coverage. One coat of a premium self-priming paint may achieve the same result as a primer coat plus one coat of standard paint. Premium paints with high hide ratings cover better in fewer coats saving money overall despite the higher per-gallon cost.
Paint Coverage by Surface Type
| Surface Type | Coverage per Gallon | Litres per 10 sq m |
|---|---|---|
| Smooth drywall | 380–400 sq ft | 0.25 L |
| Lightly textured wall | 340–380 sq ft | 0.28 L |
| Orange peel texture | 300–340 sq ft | 0.33 L |
| Heavy knockdown texture | 250–300 sq ft | 0.40 L |
| Smooth wood | 350–400 sq ft | 0.27 L |
| Rough sawn wood | 150–200 sq ft | 0.55 L |
| Smooth masonry | 200–250 sq ft | 0.45 L |
| Rough brick/stucco | 100–150 sq ft | 0.70 L |
How Paint Coverage Affects Cost
Understanding coverage rates helps you compare paint value more accurately than price per gallon alone. A $90 per gallon premium paint that covers 400 square feet in one coat costs $0.225 per square foot. A $35 per gallon budget paint that covers 300 square feet per coat and requires two coats costs $0.233 per square foot — more expensive than the premium paint.
Premium paints with high hide pigmentation — titanium dioxide — cover in fewer coats and produce richer, more accurate colours. For whole house projects or large commercial jobs, comparing cost per square foot of coverage rather than cost per gallon gives a more accurate budget picture.
Why Paint Coverage Matters for Colour Changes
Changing from a dark colour to a light colour requires the most coats — sometimes 3 or 4 — because the dark colour bleeds through light paint. Primer is essential for dark-to-light colour changes. A tinted primer matched to your topcoat colour reduces the number of topcoats needed from 3 to 2 in most cases.
Changing from light to dark requires fewer coats — typically 2 — because dark paint has high pigment concentration that covers in fewer applications. Changing between similar colours of similar darkness typically requires 1 to 2 coats with a good quality paint.
Tips to Maximise Paint Coverage
Fill and sand before painting. Smooth walls absorb less paint and achieve higher coverage rates. Fill holes, sand rough spots, and prime bare drywall patches before painting.
Use the right roller nap. A ⅜ inch nap for smooth walls, ½ inch for light texture, ¾ inch for heavy texture. The wrong nap wastes paint and reduces coverage.
Do not over-thin paint. Thinning paint too much reduces coverage and hide. Only thin when the label specifically recommends it for your application method.
Apply at the correct film thickness. Apply paint at the coverage rate on the label — not thinner to make it go further. Thin application reduces hide, durability, and colour accuracy.
Related Paint Calculators
- Paint Cost Calculator →
- Whole House Paint Calculator →
- Two Coat Paint Calculator →
- Primer Calculator →
- Textured Wall Paint Calculator →
- Free Paint Calculator →
Frequently Asked Questions
How far does a gallon of paint go?
One gallon covers 350 to 400 sq ft on smooth walls per coat. Textured walls achieve 250 to 350 sq ft per gallon. Rough masonry achieves 100 to 200 sq ft per gallon.
How many square feet does a gallon of paint cover?
350 to 400 sq ft on smooth interior walls. 300 to 350 sq ft on lightly textured walls. 150 to 200 sq ft on rough exterior wood. Always use the lower end of the range for budgeting.
How many gallons do I need for a room?
A standard 12×12 bedroom needs 1.5 to 2 gallons for two coats. A larger 16×14 living room needs 2.5 to 3 gallons. Use our room calculators for exact estimates.
Does expensive paint cover better?
Yes — premium paints with high titanium dioxide content cover better in fewer coats. A $90 premium paint often costs less per covered square foot than a $35 budget paint requiring extra coats.
How much paint do I need for two coats?
Double your single-coat quantity. If a room needs 1.5 gallons per coat, buy 3 gallons for two coats. The second coat typically uses slightly less paint as the surface is already sealed.
What affects paint coverage rate?
Surface texture (rough surfaces absorb more), application method (spraying wastes more), colour change (dark to light needs more coats), paint quality (premium paints hide better), and roller nap thickness.