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Use the Paint Needed Calculator
Paint needed depends on wall area, number of coats and coverage per tin or gallon. Two coats can nearly double the amount.
How much paint do I need?
Estimate paint from wall area, coats and coverage, then build a simple room-painting checklist.
Assumptions to check
- Coverage rates are estimates from the paint label.
- Textured, dark or porous walls may need more paint.
- Doors, windows and trim can change the final amount.
Quick checklist
- Measure wall length and height.
- Subtract large doors or windows if needed.
- Choose the number of coats.
- Check the paint coverage rate.
- Round up to avoid running short mid-wall.
Common mistakes
- Using floor area instead of wall area.
- Forgetting the second coat.
- Ignoring primer when changing from dark to light paint.
Why paint estimates go wrong
Paint is a coverage problem. The room floor area is not enough because paint goes on walls and sometimes ceilings. The calculator keeps the estimate tied to surface area, coverage and coats.
How to use the result
Treat the result as a buying guide, then check the tin size available in store. If the estimate is close to a full tin, buying the extra tin may be more practical than trying to stretch the paint.
When to add a buffer
Add a buffer for rough walls, strong color changes, patchy surfaces or rooms with many corners. A small leftover amount is usually better than an unfinished wall.