Room-wall, ceiling and whole-house paint planning.
Surface dimensions, openings, coats, product coverage and container size.
Paintable area, gallons or containers and material cost.
Primer, texture, surface porosity, color change and ceiling products may need separate estimates.
See the estimated project quantity from your measurements.
Add waste and round to complete bags, boxes, cans, bundles or delivery quantities.
Review product coverage, site conditions, local requirements and supplier details before ordering.
Estimate gallons for four room walls using dimensions, openings, coats, and your paint coverage rate.
Use the result card above to copy, print or share the estimate, then verify the final order with the product label or supplier quote.
The calculator starts with the perimeter of a rectangular room, multiplies by wall height, subtracts doors and windows, then multiplies by the number of coats. The remaining paintable area is divided by the coverage rate printed on your paint product.
A 12 × 10 ft room with 8 ft walls has 352 ft² of gross wall area before subtracting openings. Two coats require roughly twice the single-coat coverage.
Use the label: actual coverage varies with surface texture, primer, application method, color change, and product formulation. Replace the default coverage rate with the manufacturer’s number when available.
Yes, if you want a tighter estimate. Enter the combined opening area.
In the basic area calculation, yes. Real-world touchups and surface absorption can change the final amount.
Paint is purchased in fixed container sizes, so round to a practical purchase quantity and keep some material for touchups when appropriate.