Estimate interior or exterior painting cost: gallons of paint from area, coverage and coats, paint price, primer and labour per square foot. See paint cost, labour and total instantly with wastage built in.
Paint is sold by the gallon but priced by the room, and labour is the part that surprises people. The Painting Cost Calculator turns paintable area, paint coverage and number of coats into the gallons you must buy, then adds primer, a per-square-foot labour rate and wastage to reach a total.
Whether it is one accent wall or a whole exterior, the tool separates paint cost from labour so you can see which lever moves the number — and rounds the gallon count up so you actually have enough on site.
Example 1 — One room. 600 ft² walls, 350 cover, 2 coats, $32/gal, $1.5/ft² labour: ~3.4→4 gal paint ($128) + $900 labour = ~$1,060.
Example 2 — With primer. Same area, primer coat at 350 cover $22/gal adds ~1.7→2 gal ($44).
Example 3 — Deep colour. Coverage drops to 280 ft²; gallons rise to ~4.3→5 for two coats.
Example 4 — Exterior. 2,400 ft² at 2 coats, $38/gal, $2/ft² labour = ~14 gal ($532) + $4,800 labour.
Example 5 — Wastage. 10% on 4 gal = buy ~4.4→5 gallons so touch-ups don’t run short.