Painting calculator

Exterior paint calculator

Exterior paint calculator publishes formula PAINT-EXT-001 version 1.0.0.

By Feroz Shiekh · Formula PAINT-EXT-001 v1.0.0 · Internal QA complete · Planning only — not a supplier quote

FormulaPAINT-EXT-001v1.0.0

Project inputs

Enter field measurements. Imperial lengths take feet and inches. Unit conversion happens before the reviewed formula is applied.

Wall lengthft + inTotal exterior wall length being paintedftinWall heightft + inFinished wall height to the eaveftinDoorscountDoor openings to deductWindowscountWindow openings to deductDoor deductionft²Editable area deducted per doorWindow deductionft²Editable area deducted per windowNumber of coatscountCoats of selected exterior paintCoverage per gallonft²Use coverage stated on the selected exterior productWaste factor%Allowance for texture, cut-in and a spare gallon

All values can be refined when you edit the estimate. This tool does not replace field verification or local requirements.

Calculated result

2gallons

Exterior paint gallons

FormulaPAINT-EXT-001

(wall length × height − openings) × coats × (1 + waste) ÷ coverage

360 ft²

Gross wall area

228 ft²

Paintable area

501.6 ft²

Area across coats + waste

Exterior paint calculator publishes formula PAINT-EXT-001 version 1.0.0. Exterior paint calculator for whole gallons from wall length, height, openings, coats and labelled coverage. Waste, rounding and the rate you type stay on the sheet so a quote letter can still explain the number. Add the line to an estimate. Planning takeoff only — not a code approval and not a live supplier price.

Formula PAINT-EXT-001 version 1.0.0 is the arithmetic on this exterior paint calculator page and on the quote letter.
Painting takeoff: Exterior-paint gallons from wall length, height, openings, coats and labelled coverage. Interior rooms use the paint calculator. Waste and purchase rounding stay visible inputs, not hidden constants.
Add the exterior paint calculator result to an estimate, then send a quote letter — an old letter still explains itself.
You type the unit rate. Construclytic does not fetch supplier prices for this painting tool.
Planning takeoff only. The exterior paint calculator is not a code approval, mix design, or PE stamp.

Transparent cost view

No dummy crew rates. Totals stay at zero until you type a material or labour rate. Pick a currency — badges, inputs, and totals follow.

Costs use the can rate you type. Construclytic does not fetch paint prices. Primer, ceiling gallons and cut-and-roll labour stay on their own lines. Qatar and GCC planning: switch the currency control to QAR, AED, SAR, KWD, OMR or BHD. Construclytic does not publish a live Gulf plant or labour index. Plant, block and crew rates in Doha, Dubai and Riyadh vary by plant and season — replace every number with a local quote.

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Embed this calculator

<iframe src="https://construclytic.com/embed/paint-exterior" title="Exterior paint" width="100%" height="820" loading="lazy" referrerpolicy="strict-origin-when-cross-origin" style="border:1px solid #d7e0da;border-radius:16px;background:#fff;"></iframe>

Paste on a contractor site or blog. The iframe is a planning takeoff, not a bid.

How this calculator works

A transparent exterior paint takeoff.

Feroz ShiekhWritten by Feroz Shiekh · founderFormula PAINT-EXT-001 v1.0.0 reviewed Aug 31, 2026. Planning tool — not engineering advice.

Exterior wall length times height, minus door and window openings, times coats, divided by labelled exterior coverage after waste.

PAINT-EXT-001 is a straight elevation after openings, two coats at 350 ft²/gal. Interior paint uses a room perimeter. Gables are extra triangles — add them as a second line or raise waste. Trim enamel is the trim calculator.

Worked example. Example: a 40 × 9 ft elevation with two doors and six windows, two coats at 350 ft²/gal with 10% waste rounds to 2 gallons.

1. Measure each elevation. Gables are extra triangles — add them as a second line or raise waste.
2. Exterior coverage is not interior coverage. Use the can you will roll outside.
3. Trim paint is the trim calculator.

Field notes that change the number

Measure each elevation to the eave. Do not average a two-storey wall with a porch beam.
Exterior coverage is not interior coverage. Masonry and wood do not share a number.
Trim, soffit and doors as slabs are companion lines.

Common mistakes

Using the interior room calculator on an elevation.
Ignoring gables, then inflating waste to guess them.
Folding primer and finish into one exterior can count.

Gulf exterior work is often masonry or render. Replace the default coverage with the labelled exterior product; do not keep a US wood-siding figure.

Need the broader workflow? Read the painting planning guide.

How-to: How to stain a wood fence · How to estimate exterior paint

Questions

Questions about exterior paint

Is this the interior paint calculator?

No. Interior paint uses a room perimeter. This page is a straight elevation after openings.

Masonry or wood?

Coverage changes with texture. Replace the default with the labelled exterior product.

What is the formula ID?

This exterior paint calculator publishes formula PAINT-EXT-001, version 1.0.0. The ID stays on the result and on the estimate line.

Is this engineering advice?

No. The exterior paint calculator is a planning takeoff. Construclytic is not a registered engineering or contracting firm. Field checks, codes and product data still sit with you.

Does Construclytic fetch live supplier prices?

No. Costs on the exterior paint calculator use the rate you enter. Construclytic does not fetch live supplier prices.