Fresh paint.
Fresh possibilities.
Estimate Paint Materials and Costs
Estimate interior wall and ceiling paint for one wall or several rooms. Choose coats, account for primer and download an itemized material-cost PDF.
Measure
Add walls, rooms or ceilings.
Room measurements include four walls. Deduct actual door/window cutouts in square feet. Include a surface once; don’t add a room and its individual walls.
Choose paint
Keep different colors and products separate.
Two finish coats are the default. Enter your product’s coverage per coat and the price for the selected container. Changing container size does not change the price automatically.
Primer & extra
Match your surface and product instructions.
Previously painted, sound surfaces may not need separate primer. New drywall or a full skim usually needs full priming. Repairs may need spot priming. Stains, glossy finishes and major color changes may require a suitable specialty primer. “Paint and primer” does not always replace separate primer.
Application loss and touch-up reserve, added to paint and primer before rounding to containers.
Starting price allowances: $40 per wall-paint gallon, $35 per ceiling-paint gallon, $25 per primer gallon. Replace these with your store prices.
Estimate assumptions & exclusions
Paint Materials Estimate
Tools / Accessories Commonly Needed
Check what you already own. These items are not included in the material total.
Painting supplies
- Angled brush, roller frame and suitable roller covers
- Paint tray and liners or bucket and roller grid
- Extension pole, drop cloths and painter’s tape
- Paint stirrer, can opener and suitable access equipment
Preparation, when needed
- Cleaner and cloths for surface preparation
- Patching compound and putty knife for small repairs
- Sandpaper or sanding sponge
- Paintable caulk and caulk gun for suitable gaps
Plan your project
How to calculate paint and primer quantities
Measure only the surfaces you intend to paint. A room’s four walls use 2 × (room length in feet + room width in feet) × wall height in feet. A single wall uses wall length in feet × wall height in feet. A flat ceiling uses ceiling length in feet × ceiling width in feet. Deduct actual cutout area in square feet.
Finish paint (US gal) = net area (sq ft) × finish coats ÷ coverage (sq ft/US gal/coat) × (1 + extra allowance (%) ÷ 100)
Primer uses the same formula with only the primed area in square feet, primer coats and primer coverage. Spot-prime area is measured once; the calculator applies the primer coat count. Extra allowance is applied once, then each color/product is rounded up to your chosen container size.
Worked example: a 12-ft × 10-ft room
At 8-ft wall height with 40 sq ft of cutouts, walls total 312 sq ft. At two finish coats, 350 sq ft/US gal/coat and 10% extra, 1.961 US gal is needed: buy two 1-US-gal cans. At $40 per can, wall paint costs $80.
Add a 120-sq-ft ceiling at the same coat count and coverage: 0.754 US gal, rounded separately to one 1-US-gal can at $35. Full-surface primer over all 432 sq ft, one coat at 300 sq ft/US gal/coat plus 10%, needs 1.584 US gal: two 1-US-gal cans at $25 each. Total paint and primer allowance: $165.
Coats and coverage are product-specific
The starting paint rate is 350 sq ft per US gallon per coat; primer starts at 300. These are editable planning rates. Texture, porosity, application and color changes affect actual coverage. Two finish coats are a useful starting point. One-coat claims apply only under the manufacturer’s stated conditions; primer is a separate decision.
Sources: Sherwin-Williams coverage guidance; Benjamin Moore primer and coat guidance; BEHR product-specific coverage conditions; Benjamin Moore painting supplies. Planning defaults are not guaranteed coverage or current store prices.
Paint project questions
How much paint do I need for two rooms?
Add both rooms and assign their walls to the same wall paint if the product, color and sheen match. Matching wall areas combine before rounding to cans. Different products/colors and ceiling paint round separately.
Does paint and primer in one eliminate primer?
Not always. New drywall, repairs, stains and difficult finishes may need an appropriate separate primer. Follow the product’s preparation instructions. Primer coats do not replace the finish-coat count in this estimate.
Can I estimate an accent wall?
Use Individual wall, add a second wall paint product/color and assign that wall to it. Enter other walls separately so the same surface is not counted twice. Use a separate estimate for additional ceiling products.