Step by step
- Perimeter. Add the length of every wall you'll paint. A 12 × 12 ft room has a 48 ft perimeter.
- Wall area. Perimeter × wall height. 48 × 8 = 384 sq ft.
- Subtract openings. A standard door and two windows might remove around 36 sq ft — measure yours. 384 − 36 = 348 sq ft.
- Coats. Two coats doubles the painted area to 696 sq ft.
- Paint. Divide by the coverage on the product data sheet and round up. At 350 sq ft/gal: 696 ÷ 350 = 1.99 → 2 gallons.
- Labour. Divide painted area by your own measured pace and add prep. At 150 sq ft/h: 4.6 h + 2 h prep = 6.6 h.
- Price. Add paint, sundries and labour cost, then price to your target margin with the formula cost ÷ (1 − margin).
These example figures are illustrations, not typical rates. Your production rate depends on surface, height, colour change, cutting-in and crew — time a few of your own jobs and use those numbers.
What the calculator leaves to you
- Ceilings, trim, doors and cabinets — estimate each as its own line (the ScopeBid app has separate templates for these)
- Drywall repair, wallpaper removal, stain blocking and primer
- Moving furniture, protecting floors and daily setup
- Ladders, lifts or scaffolding for tall walls
Put it on a quote
A good painting quote lists the rooms and surfaces, the number of coats, who supplies the paint and colours, what's excluded, how long the price is valid and your payment terms. Check your price with the profit margin calculator, then print this estimate or save it as a PDF with the button on the result.
Common questions
How do I estimate labour for a painting job?
Measure the paintable area (wall perimeter × height, minus doors and windows), multiply by the number of coats, and divide by your own production rate in square feet per hour. Add separate hours for prep: moving furniture, masking, patching, caulking and cleanup.
How many gallons of paint do I need?
Divide the painted area (area × coats) by the coverage printed on your paint's product data sheet, then round up to whole gallons. Coverage varies by product and surface, so use the manufacturer's figure rather than a rule of thumb.
What should a painting estimate include?
Rooms or surfaces, prep work, number of coats, paint product and colour responsibility, what is excluded (e.g. ceilings, trim, drywall repair), schedule, validity period, payment terms, subtotal, tax and total.