Paint cost calculator (DIY)
Enter the room and the prices from your store. The calculator works out the gallons, rounds them up to whole cans, and adds primer and supplies. The prices filled in are only examples: type your own.
Enter your measurements
More options: Door · Window · Paint $ …
- Paint
- $80.00
- Supplies
- $30.00
- Paint to buy
- 2 gallons of paint
- Area painted
- 334 sq ft
334 sq ft × 2 coats ÷ 350 sq ft/gal → 2 gallons of paint
Paint $80.00 + supplies $30.00 = $110.00
- Priced on whole gallons. If the job needs a gallon and a quart, the quart usually costs more per ounce; buy what the room paint calculator suggests.
- Two coats of a better paint often cost less than three coats of a cheaper one: compare the coverage on the labels, not just the price.
Cost by number of coats
| Coats | Paint to buy | Total cost |
|---|---|---|
| 1 | 1 gallon of paint | $70.00 |
| 2 | 2 gallons of paint | $110.00 |
| 3 | 3 gallons of paint | $150.00 |
The prices filled in are placeholders to show how the calculator works, not what paint costs where you live. Type your store’s price per gallon (or litre) for the paint you have chosen. New to this? Paint words explained.
How the cost is worked out
paint (gal) = area × coats ÷ coverage, rounded up to whole gallons primer (gal) = area ÷ 400, rounded up total = paint × price + primer × price + supplies
The gallons are the same as the room paint calculator: a 12 × 12 room with 8 ft walls, a door and two windows takes 2 gallons for two coats at 350 sq ft per gallon (how much paint for a 12x12 room). New drywall adds a gallon of primer at the 400 sq ft per gallon on drywall-primer data sheets (how much primer for a 12x12 room).
Where the money goes
- Paint is usually the biggest line, and the one where quality changes the quantity: a paint that covers in two coats can cost less overall than a cheaper one that needs three.
- Primer is only needed on new drywall, patches, stains and big color changes.
- Supplies are a one-time cost: a roller frame, covers, a tray, an angled brush, tape and a drop cloth do many rooms.
- Your time is the rest. A bedroom is usually a weekend for one person, with the drying time between coats.
For the ceiling and trim, add them as separate items to the project list using the ceiling paint calculator and the trim paint calculator.
What you’ll need
- Paint roller frame and covers (9 in)Budget price
A sturdy 9 in frame and a few 3/8 in nap covers handle smooth drywall. Rougher walls and ceilings want 1/2–3/4 in nap, as the data sheets suggest.
See options on Amazon (opens in a new tab) - Angled sash brush (2–2½ in)Budget price
For cutting in along ceilings, corners and trim. A nylon-polyester brush is what the latex data sheets recommend.
See options on Amazon (opens in a new tab) - Paint tray and linersBudget price
Liners turn a color change or the end of the day into a two-minute job instead of a scrub at the sink.
See options on Amazon (opens in a new tab) - Canvas drop clothBudget price
Canvas stays put and soaks up drips; plastic is cheaper but slippery underfoot and spreads wet paint.
See options on Amazon (opens in a new tab) - Painter’s tape (multi-surface)Budget price
Masks trim, ceilings and glass. Pull it at an angle while the last coat is still slightly soft for the cleanest line.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How much does it cost to paint a 12x12 room yourself?
Two gallons of wall paint for two coats, plus supplies if you don’t have them, and a gallon of primer if the walls are new drywall. Put your store’s prices into the calculator for the total.
Is it cheaper to buy paint in 5-gallon pails?
Usually per gallon, yes, but only if you use most of it. Under about 3½ gallons, single gallons usually work out cheaper overall.
Does more expensive paint save money?
Sometimes. Higher-end paints often hide in fewer coats; if that saves a coat, it saves a third of the paint and a day of work. Compare the coverage and the coats on the data sheets.
Why are the prices in the calculator only examples?
Paint prices vary by brand, line, store and region, and change often. The calculator does the arithmetic; the prices have to be yours.
Sources
- Sherwin-Williams, ProMar 200 Zero VOC Interior Latex Eg-Shel (B20 series), product data sheet (opens in a new tab) — Coverage 350–400 sq ft per gallon at 4 mils wet; two coats over primer on drywall; sheen 15–20 units at 85°.
- Sherwin-Williams, ProMar 200 Zero VOC Interior Latex Primer (B28W02600), product data sheet (opens in a new tab) — Coverage 400 sq ft per gallon at 4 mils wet; one coat on drywall, then two finish coats.