Exterior calculator

Foam board

Rigid-foam sheet count from wall area after openings and the face of one panel.

Reviewed formula · v1.0.0

Project inputs

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

Wall lengthft + inTotal wall length being insulatedftinWall heightft + inFinished wall heightftinDoorscountDoor openings to deductWindowscountWindow openings to deductDoor deductionft²Editable area deducted per doorWindow deductionft²Editable area deducted per windowSheet coverageft²Face of one panel. A 4×8 sheet is 32 ft²Waste factor%Allowance for cuts at corners, bands and openings

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

Calculated result

8sheets

Sheets to order

FormulaEXT-FOM-001

(L × H − openings) × (1 + waste) ÷ sheet coverage

228 ft²

Net wall area

250.8 ft²

Area including waste

Transparent cost view

Planning rates only. Pick a currency — badges, inputs, and totals follow. Material is a rate. Labour is hours × a planning hourly rate. Equipment and delivery are this-job amounts.

Material ratePlanning · per calculated unit · USDEquipmentPlanning · this job · USDDeliveryPlanning · this job · USDLabour hoursPlanning · this jobLabour ratePlanning · per hour · USDOverhead %%Contingency %%Markup %%Tax %%

Planning defaults are office figures, not a bid. US ready-mix in 2026 often lands around $125–165 per cubic yard delivered; place-and-finish commonly $2–4 per square foot. Replace every rate with a supplier or crew quote before you send the letter.

Indicative FX as of Aug 2026. Planning conversion, not a live bank rate.

Material costUSD 680

Labour (8 h)USD 280

Direct costUSD 1,070

Overhead + contingencyUSD 107

Markup + taxUSD 141

Estimated project totalUSD 1,318

View estimate Quote / invoice Add another item

Embed this calculator

<iframe src="https://construclytic.com/embed/foam-board" title="Foam board" 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 foam board takeoff.

Wall length times height, minus door and window openings, divided by the face of one rigid-foam panel after a cutting allowance.

Worked example. Example: a 40 × 9 ft wall with two 21 ft² doors and six 15 ft² windows is 228 ft² net. 4×8 sheets at 32 ft² with 10% waste round to 8 sheets.

1. Measure the wall that receives foam, including bands if they get the same product.
2. Deduct openings, or raise waste if you run foam continuous and cut later.
3. Tape, fasteners and the cladding are separate lines.

Need the broader workflow? Read the exterior planning guide.

Questions

Questions about foam board

Polyiso, XPS or EPS?

Coverage is the sheet face. R-value and facing are a spec, not this count.

Is this batt insulation?

No. Use the insulation calculator for batts and the blown-in calculator for attics. This page is rigid boards.

What is the formula ID?

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

Is this engineering advice?

No. Construclytic is a planning website, 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 use the rate you enter. Construclytic does not fetch live supplier prices.