Detailed results and planning tools
View calculations, report and comparisons
Calculation breakdown
These values reflect the editable inputs and assumptions above.
| Quantity | Value |
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Calculation report
Includes formulas, entered assumptions, limitations and sources.
Compare scenarios
Keep up to three alternatives to compare measured values and assumptions.
Measure the surfaces you will actually paint#
Use room mode for four rectangular walls, or surface mode for a single wall, door or other rectangular surface. Deduct openings only when their surfaces will not receive the same product. Select ceilings explicitly; they have a separate paint purchase.
Calculate coats and coverage explicitly#
Room wall area = 2 × (length + width) × height − unpainted openings. Multiply net area by the selected coat count and application allowance, then divide by coverage per coat. Coverage is entered in ft² per US gallon or m² per liter.
The starting 350 ft²/US gal, two coats and 10% allowance are editable examples. Read the chosen product’s instructions and account for your surface and application method. A coverage override can be entered for each finish product; blank overrides inherit the main finish coverage.
Worked example: a room and separate ceiling#
A 12 × 10 ft room with 8 ft walls has 352 ft² of wall area. Excluding a 21 ft² door leaves 331 ft². At two coats, 350 ft²/US gal and 10% allowance, wall finish paint is 331 × 2 × 1.10 ÷ 350 = 2.081 US gal, rounded to three 1-gallon containers.
The 120 ft² ceiling at the same coverage and coat count needs 0.754 US gal, rounded separately to one 1-gallon container. These products cannot share a container merely because their combined liquid quantity fits another package arrangement.
Keep primer and colors separate#
Three wall or surface groups allow separate colors or products. Areas in one group must use the same coverage, coat count and container size. Primer has its own coverage and coats and applies to all included surfaces when enabled. Run separate scenarios when different surfaces require different primers or finish coat counts.
Enter a price for every used product to obtain a complete purchase cost. Price is per whole container; delivery/fixed cost and entered tax are then applied. Currency changes the label, not the exchange rate.
Sources and surface preparation#
Benjamin Moore’s calculator, BEHR’s product specifications and USG’s new-wallboard guidance provide manufacturer context. Follow the coating system’s preparation and primer instructions. For panel quantity before painting, use the Drywall Calculator.