Paint Cost Calculator – Gallons, Price & Room Coverage Estimate
Calculate how much paint you need and what it will cost based on wall area, number of coats, and paint quality. Supports economy, standard, and premium paint tiers.
Paint Cost Calculator Formula
Gallons = Ceiling((Area x Coats) / Coverage); Cost = Gallons x Price per Gallon
How to Calculate Paint Cost
- 1. Calculate total coverage needed: Total = Wall Area x Number of Coats
- 2. Determine gallons: Gallons = Ceiling(Total / Coverage per Gallon)
- 3. Apply quality pricing: Economy=$25/gal, Standard=$45/gal, Premium=$65/gal
- 4. Total cost = Gallons x Price per gallon
- 5. Rooms worth = Wall Area / 800 (average room is ~800 sq ft of wall)
Example Calculation
Let's say you're painting 1,600 sq ft of walls with 2 coats using standard quality paint.
- wallArea: 1600
- numCoats: 2
- quality: standard
- coveragePerGallon: 400
8 gallons needed, estimated cost: $360.00, covers approximately 2.0 rooms
Tips
- Always buy a little extra paint — most professionals recommend rounding up to account for touch-ups
- Two coats are standard for most interior painting — the second coat ensures even coverage and color depth
- Premium paints often cover better and may require fewer coats, potentially saving money despite the higher per-gallon price
- A typical 10x12 foot room with 8-foot ceilings has about 800 sq ft of wall area (minus windows and doors)
Frequently Asked Questions
How much paint do I need for a 12x12 room?
A 12x12 room with 8-foot ceilings has approximately 384 sq ft of wall area (minus doors and windows, about 320 sq ft). For 2 coats at 400 sq ft/gallon coverage, you need about 2 gallons of paint.
How much does it cost to paint the interior of a house?
For a 2,000 sq ft home with approximately 4,800 sq ft of wall area, using standard quality paint at 2 coats, expect to spend about $1,080 on paint alone. Professional labor typically adds $2,000-$5,000 depending on your area.
How many coats of paint should I apply?
Two coats is the standard for most interior painting. You may need a third coat when painting over dark colors with light paint, or when using low-opacity colors like reds and yellows.
Does paint quality really matter?
Yes. Premium paints typically have better coverage, durability, and color retention. They often require fewer coats and last longer, which can make them more cost-effective over time despite the higher upfront price.