How much paint do I need for a 12x12 room?

For a standard 12x12 room with 8-foot ceilings, you'll need approximately 2-3 gallons of paint for two coats. The exact amount depends on paint type (flat vs. gloss), surface texture, and the number of doors and windows. Our calculator automatically accounts for these factors and includes a 10% waste factor.

How many square feet does a gallon of paint cover?

Paint coverage varies by type: Flat paint covers ~400 sq ft/gallon, Eggshell ~375 sq ft/gallon, Satin ~350 sq ft/gallon, Semi-gloss ~325 sq ft/gallon, and Gloss ~300 sq ft/gallon. Textured or rough surfaces require 15-25% more paint than smooth surfaces.

Do I need primer before painting?

Primer is recommended when painting over bare drywall, making dramatic color changes, painting over glossy surfaces, or when the surface has stains. Primer improves paint adhesion and coverage, often requiring fewer topcoats. Our calculator includes primer cost estimation when selected.

How much does it cost to paint a room?

Paint costs vary by quality and brand, typically ranging from $25-$60 per gallon. For a standard 12x12 room, expect to spend $70-$200 on paint (including primer and supplies). Premium paints cost more but often provide better coverage and durability, potentially saving money long-term.

Should I buy gallons or quarts of paint?

For large projects (over 150 sq ft), gallons are more economical. For small projects, touch-ups, or accent walls, quarts may be sufficient. Our calculator shows both options and recommends the most cost-effective choice. Gallons typically cost $25-$50, while quarts cost $10-$15.

Calculators ConstructionPaint Calculator

Paint Calculator

Calculate paint quantity, coverage area, and total cost for your painting project. Supports multiple coats, primer, and various paint types.

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How to Use the Paint Calculator

Choose Calculation Type

Select whether you're painting a full room, single wall, or have a custom area measurement.

Enter Measurements

Input your room or wall dimensions in feet. For rooms, include ceiling height and count doors and windows.

Select Paint Settings

Choose paint type (affects coverage rate), surface type (smooth/textured/rough), number of coats, and whether primer is needed.

Enter Pricing

Input current paint prices from your local store to get an accurate cost estimate including supplies.

Paint Type Guide

Flat/Matte Paint

Coverage: ~400 sq ft/gallon

Best for ceilings and low-traffic areas. Hides imperfections well but difficult to clean.

Eggshell Paint

Coverage: ~375 sq ft/gallon

Low sheen finish, good for living rooms and bedrooms. Easy to clean with gentle wiping.

Satin Paint

Coverage: ~350 sq ft/gallon

Popular for high-traffic areas like hallways and kids' rooms. Durable and washable.

Semi-Gloss Paint

Coverage: ~325 sq ft/gallon

Great for kitchens, bathrooms, and trim. Moisture-resistant and very easy to clean.

Gloss Paint

Coverage: ~300 sq ft/gallon

Highest sheen, best for doors and cabinets. Extremely durable but shows imperfections.

Professional Painting Tips

Always Use Primer

Primer ensures better paint adhesion and can reduce the number of topcoats needed, especially on bare drywall or when making dramatic color changes.

Buy Extra Paint

Our calculator includes 10% waste factor, but always buy an extra quart for future touch-ups. Paint batches can vary slightly in color.

Test Your Color First

Paint a small test area or use sample pots to see how the color looks in your lighting before committing to gallons.

Quality Matters

Premium paints ($40-60/gallon) often provide better coverage and durability than budget options ($20-30/gallon), potentially saving money long-term.

Proper Preparation

Clean walls, fill holes, and sand rough spots before painting. Good prep work ensures professional-looking results.

Two Coats Minimum

Most painting projects require at least two coats for even coverage and color saturation. Don't skimp on the second coat.

Paint Cost Saving Tips

Shopping Strategies

•Buy during sales (Memorial Day, July 4th, Labor Day often have 20-40% off)
•Check for "oops" paint (mixed colors) at 50-75% off for non-critical rooms
•Buy in bulk if painting multiple rooms - contractors often get 10-15% discounts
•Compare prices between big box stores - they often price match

Application Tips

•Use quality rollers and brushes - cheap tools waste paint and time
•Properly prime to reduce topcoat needs from 3 coats to 2
•Don't over-load rollers - thin, even coats use less paint
•Save leftover paint properly for touch-ups instead of buying more later

Paint Needed for Common Room Sizes

Room Size	Wall Area	Paint Needed (2 coats)	Estimated Cost*
10x10 (8' ceiling)	~280 sq ft	2 gallons	$90-$150
12x12 (8' ceiling)	~350 sq ft	2-3 gallons	$110-$180
15x15 (8' ceiling)	~440 sq ft	3 gallons	$130-$210
20x20 (9' ceiling)	~680 sq ft	4-5 gallons	$180-$290
12x18 (10' ceiling)	~560 sq ft	3-4 gallons	$150-$240

* Cost includes paint, primer, and basic supplies. Prices based on mid-range paint quality ($35-40/gallon).