Interior Painting Calculator 2025

Example 1: 12×14 bedroom, 8 ft ceiling, mid-grade paint, DIY

• • Wall area: 2×(12+14)×8 − 1 door (21) − 2 windows (30) = 365 sqft
• • Gallons (2 coats, 10% waste): 365 ÷ 350 × 2 × 1.10 = 2.3 → buy 3 gallons
• • Material cost (mid $38/gal): 3 × $38 = $114
• • Total DIY cost: ~$114

Example 2: 3-room home repaint, hiring a painter

• • Rooms: 12×14, 10×12, 15×20 — total wall area ~1,100 sqft
• • Gallons (2 coats + waste): ~7 → buy 7 gallons mid-grade = $266
• • Labor (1,100 sqft × $3.50 avg): $3,850
• • Total hired cost: ~$4,116

How much paint do I need for a 12×14 room?

A standard 12×14 ft room with 8 ft ceilings has approximately 416 sq ft of wall area (minus doors and windows). With 2 coats and 10% waste, you need about 2.6 gallons — so buy 3 gallons. If painting the ceiling too, add another gallon (168 sqft / 350 coverage ≈ 0.5 gallons, buy 1).

How much does it cost to paint a room in 2025?

Hiring a painter for a standard 12×14 bedroom costs $300–$600 for walls only, or $400–$800 including ceiling. National average painter rates are $2.50–$4.50 per square foot of paintable surface. Paint material (mid-grade) adds $100–$150. Total: $400–$950 per average bedroom.

How many gallons of paint do I need for an average house?

A typical 2,000 sqft home with 8 ft ceilings needs approximately 10–12 gallons for walls (2 coats) and 3–4 additional gallons for ceilings. Total: 13–16 gallons for a full interior repaint. Premium or dark colors may need a third coat, increasing usage by 30–50%.

What is paint coverage per gallon?

Standard quality interior latex paint covers 350–400 sq ft per gallon per coat. Cheap paint may cover only 250–300 sqft. Textured surfaces (orange peel, knockdown, popcorn ceilings) reduce coverage by 20–30%. This calculator uses 350 sqft per gallon as the industry standard conservative estimate.

Is it cheaper to paint yourself or hire a painter?

DIY saves the $2.50–$4.50/sqft labor cost. For a 1,000 sqft of wall area, that is $2,500–$4,500 in savings. However, professional painters work faster (quality crew finishes a 3-bedroom home in 2–3 days) and achieve better results on ceilings and trim. For large projects or rental properties, hiring often makes sense economically when you value your time at $25+/hour.

How many coats of paint do I need?

Most interior repaints need 2 coats for even coverage. Going from dark to light color may need 3 coats. Fresh drywall requires a primer coat first (count this as coat 1). High-traffic areas (hallways, kids' rooms) benefit from a third coat of washable paint. This calculator defaults to 2 coats — adjust based on your specific situation.

How do I calculate paintable wall area?

Formula: Paintable Area = 2 × (Length + Width) × Height − (Doors × 21 sqft) − (Windows × 15 sqft). A standard door is 21 sqft (36"×80"). A standard window is 15 sqft (36"×60"). For an L-shaped or irregular room, calculate each rectangular section separately and add them.

What is the difference between wall paint and ceiling paint?

Ceiling paint is typically flat finish (no sheen) to hide imperfections and resist glare. It is thicker than wall paint, providing better one-coat coverage. You cannot use ceiling paint on walls — the flat finish shows fingerprints and scuffs easily. Wall paint comes in flat, eggshell, satin, and semi-gloss finishes; satin is best for most rooms.

Should I paint trim the same color as walls?

Painting trim the same color as walls (tone-on-tone) creates a modern, seamless look popular in 2024–2025. Traditional design uses bright white trim against colored walls. Trim is typically semi-gloss or gloss finish for durability and easy cleaning, regardless of color. Budget about 1 gallon per 200–300 linear feet of trim.

How accurate is this interior painting cost calculator?

This calculator uses 2025 national average data from HomeAdvisor and Angi, and the industry-standard 350 sqft/gallon coverage formula. Actual costs vary based on your local labor market (rates in NYC or SF run 50–80% above national average), paint brand choice, surface condition, and room complexity (vaulted ceilings, heavy texture). Use these estimates for budgeting — always get 2–3 contractor quotes for your final decision.