The Interior Painting Cost Calculator estimates the cost to paint the inside of a home. The rooms mode calculates walls (and ceilings if you choose) for one room or several similar rooms, then adds paint and labor. The whole-house mode multiplies the home’s floor area by a price per square foot of floor.
Interior Painting Cost Calculator
Estimate interior painting cost for a room or whole house — walls, ceilings, paint and labour.
Allows one door and two windows per room.
Each room allows for one door and two windows. Paint prices and labor rates are examples — enter your local quotes.
Formula
Rooms: Paintable = rooms × (2(L + W) × H − 21 − 2 × 15 (+ L × W ceiling))
Total = ⌈paintable × coats ÷ coverage⌉ × price + paintable × labor rate
Whole house: Total = floor area × price per ft² of floor
How the Calculation Works
Step 1: Wall area = perimeter × height, minus one door and two windows.
Step 2: Add the ceiling if selected, and multiply by the number of similar rooms.
Step 3: Round paint up to whole gallons and add labor per ft² of painted surface.
Example Calculation
One room
Given (example prices): 14 × 12 ft, 8 ft walls, ceiling painted, 2 coats, 350 ft²/gal, $45/gal, $1.75/ft² labor
- Walls = 416 − 21 − 30 = 365 ft²; ceiling = 168 ft²; total 533 ft²
- Gallons = 1,066 ÷ 350 = 3.05 → 4 → $180
- Labor = 533 × 1.75 = $932.75
- Total = $1,112.75
Whole house
Given: 2,000 ft² home at an example $3.50 per ft² of floor
Total = $7,000
What Affects Interior Painting Cost
- Ceiling height and stairwells.
- Trim, doors and cabinets, often priced separately.
- Wall repairs and priming.
- Moving furniture and protecting floors.
- Color changes that need extra coats.
If you get a quote per ft² of floor, use the whole-house mode; if the quote is per ft² of wall, use the rooms mode.
Frequently Asked Questions
How much does it cost to paint a room?
Paint for the walls (and ceiling) plus labor on the painted area — the calculator does both.
How much does it cost to paint the interior of a house?
Floor area × your local price per ft² of floor gives a quick estimate.
Does wall area differ from floor area?
Yes — walls are usually larger; a 14 × 12 room has 168 ft² of floor but about 365 ft² of paintable wall.
Are ceilings included?
Choose Yes to add them.
Can I include several rooms?
Enter the number of similar rooms, or calculate different rooms separately and add them.