🏠 Enter Your Room Dimensions
Fill in the fields below — the estimate updates automatically as you type.
How does it calculate?
We use the same formula professional painters use — no magic, just math.
1
Room Perimeter × Height
Total wall area in square feet
2
Subtract Openings
20 sq ft per door, 15 per window
3
Multiply by Coats
Divide by 350 sq ft per gallon
4
Add 10% Waste
For touch-ups, spills, and cuts
🪣
Your Estimate
Updates as you type
—
gallons needed
📐
Enter room dimensions above
Your estimate will appear here instantly
💡 Pro Tips
- Always round up to the nearest gallon — you can't paint half a wall
- Buy paint from one batch — different dye lots look slightly different
- Keep leftover paint — label the can with the room for future touch-ups
- One gallon of primer goes further than paint — covers ~400 sq ft
⚠️ Don't Forget
- Primer is NOT included in this estimate
- Textured walls use 10–20% more paint
- Very dark colors may need 3+ coats over light walls
Need the full how-to guide?
Read: Interior Painting Guide →