If you’re planning a painting project, one of the first questions you’ll likely ask is: how many square feet does a gallon of paint cover?

The quick answer is:

$1\text{ Gallon of Paint}\approx350\text{ to }400\text{ Square Feet}$ 1 Gallon of Paint≈350 to 400 Square Feet

So:

One gallon of paint typically covers 350–400 square feet with one coat.

Actual coverage can vary depending on the surface, paint quality, and application method.

Quick Answer

Most paint manufacturers estimate coverage at:

350 to 400 square feet per gallon
For smooth, properly prepared surfaces
With a single coat of paint

A commonly used planning figure is:

$1\text{ Gallon}=400\text{ Square Feet}$ 1 Gallon=400 Square Feet

How Many Square Feet Does a Gallon of Paint Cover?

The exact coverage depends on several factors, but most interior and exterior paints cover approximately:

Paint Amount	Coverage
1 Gallon	350–400 sq ft
2 Gallons	700–800 sq ft
5 Gallons	1,750–2,000 sq ft

For rough planning, many contractors use 400 square feet per gallon.

One Coat vs. Two Coats

Many painting projects require two coats.

If one gallon covers:

$400\text{ Square Feet}$ 400 Square Feet

with one coat, it will effectively cover:

$200\text{ Square Feet (Two Coats)}$ 200 Square Feet (Two Coats)

when applying two coats.

Paint Coverage Formula

Estimating paint requirements is simple.

Standard Formula

Use:

$\text{Gallons Needed}=\frac{\text{Total Square Feet}}{400}$ Gallons Needed=400Total Square Feet

Example Calculation

Suppose your walls total:

$1200\text{ Square Feet}$ 1200 Square Feet

Then:

$1200\div400=3\text{ Gallons}$ 1200÷400=3 Gallons

Result:

Approximately 3 gallons for one coat.

Paint Coverage Chart

Gallons of Paint	Approximate Coverage
1	350–400 sq ft
2	700–800 sq ft
3	1,050–1,200 sq ft
4	1,400–1,600 sq ft
5	1,750–2,000 sq ft

This chart assumes smooth surfaces and proper application.

Factors That Affect Paint Coverage

Several variables influence how far a gallon of paint will go.

Surface Texture

Rough surfaces absorb more paint.

Examples include:

Brick
Stucco
Textured drywall

These surfaces may require additional paint.

Paint Type

Different paints have different coverage rates.

Examples:

Primer
Flat paint
Satin paint
Semi-gloss paint

Always check manufacturer specifications.

Number of Coats

Two coats generally provide:

Better color consistency
Improved durability
More uniform appearance

However, they double paint consumption.

Application Method

Coverage varies depending on whether paint is applied with:

Roller
Brush
Sprayer

Sprayers often use more paint due to overspray.

How to Calculate Paint Needed

Step 1: Measure Wall Area

Multiply:

Length × Height

for each wall.

Step 2: Add Total Square Footage

Combine all wall areas.

Step 3: Divide by Coverage Rate

Use:

$\text{Square Feet}\div400$ Square Feet÷400

to estimate gallons required.

Common Paint Estimation Mistakes

Avoid these common errors.

Ignoring Multiple Coats

Many homeowners calculate for only one coat.

Forgetting Textured Surfaces

Rough materials consume more paint.

Not Accounting for Waste

Small losses occur during application and cleanup.

Skipping Primer

Unprimed surfaces often require additional paint.

Expert Tips for Buying Paint

Professionals recommend these best practices.

Buy Slightly More Than Needed

Extra paint helps with touch-ups later.

Check Manufacturer Coverage Ratings

Coverage varies by brand and product line.

Use Quality Paint

Higher-quality paints often provide better coverage.

Measure Carefully

Accurate measurements prevent overspending.

Real-World Example

Suppose you’re painting a room with:

16-foot walls
10-foot ceilings
Total wall area of 800 square feet

Calculation:

$800\div400=2\text{ Gallons}$ 800÷400=2 Gallons

Result:

Approximately 2 gallons for one coat
About 4 gallons for two coats

FAQs

1. How many square feet does one gallon of paint cover?

Most paints cover approximately 350–400 square feet per gallon.

2. How much paint do I need for a 1,200-square-foot area?

Typically about 3 gallons for one coat.

3. Does exterior paint cover the same area?

Coverage is often similar, but rough exterior surfaces may reduce coverage.

4. How many coats should I apply?

Most painting professionals recommend two coats.

5. Should I buy extra paint?

Yes. Having extra paint is useful for future touch-ups and repairs.

Conclusion

Understanding how many square feet does a gallon of paint cover helps you estimate costs, purchase the right amount of paint, and avoid project delays. The standard coverage is: