Painting tools and calculators
A painting calculator's job is to tell you whether a quote is in a sane range, not to replace an estimate. Using published 2026 figures - about $1-$4 per square foot of floor space for interiors and $2.20-$4.40 per square foot for exteriors - you can bracket a likely cost in a couple of minutes and spot a bid that's far outside it.
Start with the measurement that matches the quote. Interior estimates are often quoted per square foot of floor area; exterior estimates are usually per square foot of wall surface. Mixing them up is the fastest way to conclude a fair bid is a rip-off, or vice versa.
For a rough interior bracket, multiply your finished floor area by $1-$4 using This Old House's 2026 range, and treat the top of the range as "walls, ceilings and trim, in a house that needs real prep." A whole-interior job in that source runs $1,800-$10,000.
For exteriors, This Old House puts the range at $2.20-$4.40 per square foot, or roughly $4,400-$8,800 on a typical 2,000-square-foot home. Add for two-story access, extensive wood repair, and any home built before 1978 where lead-safe practices apply.
Calculators cannot see your substrate. Rot, failed caulk, chalking, moisture and previous bad paint jobs are the variables that move a real quote, and none of them show up in a formula. Use the number as a bracket, then let three contractors walk the house.
Choosing painting tools
The judgement calls that decide the bill, before anyone quotes you.
- Confirm which square footage a quote uses Floor area or painted surface area. This single question resolves most "why is this bid so different" confusion.
- Bracket, don't predict Produce a low and a high. If all three bids land inside your bracket, price isn't your deciding factor - scope and references are.
- Add a line for prep unknowns On any older exterior, assume some carpentry. Ask each bidder for their hourly change-order rate rather than a guess.
- Factor in lead-safe work Pre-1978 homes require certified firms and containment for covered work. That's real labor, and it belongs in your bracket.
- Don't use a calculator to negotiate Waving a national average at a local contractor rarely produces a better job. Use it to spot outliers, then buy on scope.
All painting tools
Paint Cost Calculator
Paint Quantity Calculator
Interior Painting Estimator
Exterior Painting Estimator
Where these figures come from
Sources last checked
- This Old House - Interior Painting Cost (updated 04/20/2026) · retrieved 2026-07-25
- This Old House - Cost to Paint House Exterior (updated 03/06/2026) · retrieved 2026-07-25
- Improovy - Average Interior Painting Cost · retrieved 2026-07-25
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