Painting Job Estimate Calculator

How to use the painting job estimate calculator

1. Measure the room the same way as the paint-quantity page: length, width, wall height, doors and windows (21 sq ft and 15 sq ft openings).
2. Set the crew’s production rate and labor rate. The 150 sq ft per hour default is a CalcTheJob starting point for a typical two-coat interior wall. Change it. Hours are wall area divided by that rate; coats change the paint quantity, not the hours, unless you lower the rate for extra coats.
3. Set overhead and profit as percentages you actually use. They are applied in sequence: (labor + materials) × (1 + overhead) × (1 + profit). For an owner-side installed price from published guides, use the interior painting cost calculator. For gallons only, use the paint calculator.

Labor, materials, overhead and profit

Labor hours equal wall square footage divided by the production rate. Materials equal (wall area × coats ÷ coverage) × paint price per gallon, using the same 350 sq ft per gallon default as the paint calculator. Those two lines are the job’s direct cost. Overhead covers the shop, insurance, vehicles and unpaid time; profit is what the business keeps after that. They are separate percentages, applied in that order, and both are yours to edit. This page does not use a single catch-all multiplier, and it is not a substitute for a local labor survey or a published estimating standard such as a PDCA guide (those documents are often paywalled and are not copied here).

A worked example: 12 × 12 ft bedroom

The room has 348 sq ft of wall after one door and one window. At the 150 sq ft per hour planning starting point the job is 2.32 hours. At the $65 per hour example default, labor is $150.80. Two coats at 350 sq ft per gallon are 1.99 gallons; at the $40 per gallon example default, materials are $79.54. Direct cost is $230.34. Fifteen percent overhead is $34.55, and ten percent profit on the result is $26.49, for a suggested bid of $291.38. Compare that with the owner-side walls-only typical of $396 on the interior painting cost calculator for the same room — the two pages answer different questions, and a real bid will also include travel, prep and a minimum job charge.

Sources & assumptions

How this calculator gets its numbers. Full method: our methodology.

• Labor hours = wall square footage ÷ a user-editable production rate. The default 150 sq ft per hour is a CalcTheJob planning starting point for a typical two-coat interior wall, not a published production standard.
• Materials use (wall area × coats ÷ coverage) × paint price. The default coverage is 350 sq ft per gallon per coat, the low end of the 350–400 sq ft/gal printed on several Sherwin-Williams interior latex data sheets at 4 mils wet — the same default as the paint-quantity page. Door and window openings are 21 sq ft and 15 sq ft. Coats change the paint quantity, not the hours, unless the production rate is lowered.
• Overhead is applied to labor plus materials, then profit is applied to that subtotal. Both percentages are user-editable. This is a contractor worksheet, not an owner-side published room price.
• The $65 per hour labor rate and $40 per gallon paint price that the form starts with are CalcTheJob example defaults for you to edit, not published labor or material surveys.

Sources

1. Sherwin-Williams, Duration Home Interior Latex Flat (A95 Series) product data sheet. Coverage 350–400 sq ft per gallon at 4 mils wet, 1.6 mils dry. This page uses the 350 sq ft low end as the default, matching the paint-quantity calculator.
2. Benjamin Moore, Regal Select Interior technical data sheet. Spread rate 400–450 sq ft per gallon — context for the default; the calculator starts at 350, and the can’s label wins.

Last reviewed November 12, 2026. Your own rates and production data win.