Hail Damage Assessment Calculator

What this calculator estimates

This calculator produces a claim-grade hail damage estimate in 2026 US dollars across three tiered outcomes:

• Spot repair — selective shingle replacement for marginal damage on a single windward slope.
• Partial-slope replacement — strip and re-cover only the slopes that took meaningful damage.
• Full replacement — slope-matching is impossible (discontinued shingle color, deteriorated mat, code-of-loss clause), so the whole roof is replaced.

It separates the bill into roof, gutters, siding, windows, skylights, supplement labor (for adjuster supplements that re-inspect after initial scope), and permit fees. It also subtracts the policy deductible to project the insurer-paid portion.

How to use it

1. Enter roof area in square feet. Use the roof square footage calculator if you don’t know it.
2. Pick roof material. Asphalt 3-tab and architectural are the most claim-prone. Metal dents but rarely fails functionally. Slate is the most hail-resistant common roof.
3. Pick the largest hailstone size observed. Marble, quarter, golf, tennis, and baseball reference sizes follow the Haag Engineering / NOAA SPC scale. Newscast photos with rulers, social-media posts, or NOAA’s preliminary storm reports document the size on a given date.
4. Set roof age class. Older roofs are more brittle and adjusters more readily approve full-replacement claims at the 13–20 year mark.
5. Pick how many slopes took damage. Hail comes from one direction (the prevailing wind), so a typical hail event impacts 1–2 of a 4-slope roof more severely than the others.
6. Toggle collateral damage — gutters, siding, windows, skylights. Collateral usually corroborates the roof claim and is typically included on the same claim.
7. Enter supplement adjuster hours if you anticipate a re-inspection after the initial scope.

Typical 2026 US hail damage claim ranges

These ranges reflect 2026 nationwide pricing from NICB Hail Loss Report, Verisk PCS data, and Q1 2026 quotes from major insurer preferred-vendor networks (State Farm, Allstate, Farmers, USAA, Liberty Mutual).

Add 20% for two-storey access and 45% for three-storey or higher.

Cost drivers

Hailstone size. This is the single largest cost driver. Damage scales steeply, not linearly, with hailstone diameter — IBHS impact tests show kinetic energy at impact scales with mass × velocity², and mass scales with diameter cubed. A 2-inch hailstone delivers roughly 8× the kinetic energy of a 1-inch hailstone at the same fall velocity. Document the size with a ruler and a date stamp.

Roof material. Class-4 impact-rated asphalt shingles (UL 2218 Class 4) survive 2-inch steel-ball drop tests; Class-3 survives 1.75-inch; standard Class-1 survives 1.25-inch only. Concrete and clay tile shatter at marginal hail sizes. Standing-seam metal dents but rarely fails functionally — most insurers consider metal denting cosmetic unless paint film is breached. Slate at 1/4-inch thickness is the most resistant common covering. Flat-roof TPO and EPDM are very resistant to hail because their flexibility absorbs impact.

Roof age and condition. ASTM D3161 and UL 2218 testing show 8–12-year asphalt shingles lose 15–20% of impact resistance. Past-useful-life roofs (20+ years) are commonly approved for full replacement at marginal hail sizes because the underlying mat is already too brittle to verify slope-only scope. ACV-coverage policies (now common on roofs over 10–15 years old in hail-prone states) depreciate the payout — a 15-year-old roof under ACV coverage may settle for 40–50% less than under RCV.

Slopes impacted. Hail arrives at the roof from one direction (the storm’s prevailing wind). A 4-slope roof typically takes 60–80% of impacts on the windward face, 15–25% on the two side faces, and almost none on the leeward face. This is why partial-slope scope is the most contested tier — homeowners want full replacement for color match while insurers want partial-slope scope to limit payout.

Slope-matching constraint. When the impacted slopes need replacement but the discontinued shingle color or weathering pattern makes match-and-blend visually impossible, many states have code-of-loss matching laws (the “Like Kind and Quality” clause in HO-3 policies) that force full replacement. Texas, Florida, California, and Iowa have explicit matching laws. Other states default to insurer discretion. The slope-matching issue is the single biggest driver of partial-to-full scope upgrades in 2026 claims.

Collateral damage. Hail rarely damages only the roof. Bent gutters, denting on aluminum or steel siding, pitting on vinyl siding, torn window screens, broken windows, cracked skylights, and bent HVAC condenser fins are all common. Including collateral on the claim corroborates the roof damage and typically raises total settlement by 25–60%.

Deductible structure. Standard HO-3 deductibles in 2026 average $1,500 to $2,500 nationally but jump to 1–5% of dwelling coverage in storm-prone states (TX, OK, KS, CO, NE, MO, IA, MN). On a $400,000 dwelling with a 2% wind/hail deductible, the deductible is $8,000 — substantially reducing or eliminating insurer payout on smaller claims.

US codes, standards, and references

• IRC R905.2.8 — Asphalt shingle installation requirements.
• UL 2218 — Standard for Impact Resistance of Prepared Roof Covering Materials (Class 1–4).
• ASTM D3161 — Standard test method for wind-resistance of steep-slope roofing products.
• ASTM D7158 — Standard test method for wind-resistance of asphalt shingles (uplift force per unit length).
• NOAA SPC Storm Reports — Daily preliminary hail reports with size classifications.
• NICB Hail Loss Report (annual) — Insurance industry hail-claim statistics by state.
• Haag Engineering Roof Damage Assessment Course — Industry-standard adjuster training reference for distinguishing functional vs cosmetic damage.
• IBHS Insurance Institute for Business & Home Safety — FORTIFIED Roof program documents Class 4 retrofit standards.

The IBHS recommends Class 4 impact-rated shingles in any state with a 25-year hail-event probability above 50% (most of the central US). Insurers often offer 5–25% premium discounts for documented Class 4 roof installations.

Diagnostic step-by-step

1. Photograph the storm. Date-stamped photos of the hail itself (with a ruler or coin for scale) are gold-standard evidence.
2. Pull the NOAA SPC preliminary storm report for your zip code on the storm date. Save the PDF.
3. Walk the property within 7 days with date-stamped photos: roof slopes from ground level, gutters, siding on all elevations, screens, windows, skylights, HVAC condenser, and any outdoor furniture or vehicles.
4. Get a free roofer inspection within 14 days. Most reputable roofers will document damage with chalk-marked impact counts per 10x10 test square per slope.
5. File the claim within 30 days of the storm via the carrier app or phone.
6. Be present for the adjuster inspection. Walk the roof with them (if safe). Have your roofer present for adjuster meetings.
7. Get the scope and estimate in writing. Compare against your roofer’s documentation. Supplement if scope is short.
8. Invoke the appraisal clause if scope is disputed and you and the adjuster cannot resolve within 30 days. Both sides hire adjusters; both adjusters select a neutral umpire.

Avoiding scams and overcharging

The post-hail-storm roofing market is one of the largest contractor-fraud zones in the US. Red flags:

• Door-knocking contractors offering “free inspection” — many file claims without authorization or invent damage.
• Pressure to sign a contingent contract before the claim is approved.
• “Free roof” or “we’ll cover your deductible” offers — both are insurance fraud in most states.
• Out-of-state contractors with no local license, no permanent local office, and no proof of insurance.
• Cash-only or wire-transfer demands.
• Failure to provide written, itemized estimates.

Use a local roofer with at least 5 years of in-state operation, a state contractor license, proof of liability and workers’ comp insurance, and verifiable BBB / Google reviews from local addresses. Get three written estimates.

Related calculators and guides

• Roof replacement cost calculator — full-replacement scenario costs by material
• Roof leak repair cost calculator — when hail damage causes interior leaks
• Roof flashing cost calculator — flashing replacement during hail-claim re-roof

Sources: 2026 NICB Hail Loss Report; Verisk PCS hail-event data; UL 2218; ASTM D3161, D7158; IRC 2024 R905.2.8; NOAA SPC Storm Reports; Haag Engineering Roof Damage Assessment Course; IBHS FORTIFIED Roof program; Q1 2026 quotes from State Farm, Allstate, Farmers, USAA, and Liberty Mutual preferred-vendor networks.