Hail usually starts reliably damaging roofs at around 1 inch in diameter (about quarter‑size), and becomes very likely to cause serious damage once it reaches 1.5–1.75 inches (ping‑pong to golf‑ball size).

Quick Scoop

Typical damage thresholds (general rule of thumb):

  • Under 0.5 inch (pea‑size):
    Usually just cosmetic, if anything; may scuff shingles or ding softer materials but major damage is uncommon.
  • 0.75–1 inch (penny to quarter‑size):
    This is where you should start paying attention. Older, brittle, or low‑quality asphalt roofs can show granule loss, small cracks, and dents in soft metals (vents, gutters).
  • 1–1.25 inches (quarter to half‑dollar):
    Widely considered the point where hail is “severe” and can crack shingles, bruise underlayment, and dent metal roofs and flashing on many homes.
  • 1.5–1.75 inches (ping‑pong to golf‑ball):
    High likelihood of significant roof damage: torn or fractured shingles, broken tiles, dented or punctured metal, and damaged vents and skylights.
  • 2.5 inches and larger (tennis ball, baseball, softball):
    These storms can cause widespread destruction and often lead to full roof replacement, even on newer or impact‑rated materials.

Why size isn’t the only factor

The hail size that will damage your roof can be higher or lower than these averages depending on:

  • Roof material:
    • Standard asphalt shingles are more vulnerable around 1 inch and up.
* Impact‑resistant shingles or thick metal roofs usually hold up longer but can still be dented or damaged by larger stones.
  • Roof age and condition:
    Older, sun‑baked, or previously damaged roofs can be harmed by smaller hail (even 0.75 inch) that might not bother a newer roof.
  • Wind speed and direction:
    Strong horizontal winds can drive even smaller hail into the roof at higher speed and at angles that increase impact force.
  • Storm duration and intensity:
    A short burst of big hail may do less overall harm than 20 minutes of repeated impact with slightly smaller stones.

An example: a 12‑year‑old asphalt roof in a windy storm with 0.75–1 inch hail might see bruised shingles and granule loss, while a new, Class 4 impact‑resistant roof might only show minor cosmetic marks under the same storm.

Common guidance from roofing pros

Roofing and insurance sources generally agree on these points:

  1. 1 inch is the key threshold.
    Many contractors and insurers treat quarter‑size hail as the lower bound where functional roof damage becomes likely, not just cosmetic.
  1. Smaller hail can still matter.
    Pea‑ to nickel‑size hail might not crack shingles but can dislodge granules, weaken the roof over time, and dent soft metals (gutters, downspouts, vents).
  1. Golf‑ball‑size and up is serious.
    Once hail reaches roughly 1.75 inches, many roofs see visible, claim‑worthy damage, including broken tiles and compromised underlayment.
  1. Roof inspections are recommended after bigger storms.
    If you see quarter‑size or larger hail on the ground, or neighbors getting inspections, it’s smart to have a qualified roofer check for bruised shingles, soft spots, and damage to flashing and vents.

Mini FAQ

Q: So, what size hail damages roofs most of the time?

  • Around 1 inch (quarter‑size) is where roof damage becomes common , especially on asphalt shingles or older roofs.

Q: Can pea‑size hail hurt my roof?

  • It usually won’t cause major structural damage, but in combination with strong wind, age, or prior wear, it can contribute to surface wear and minor issues.

Q: When should I call someone to check my roof?

  • If hail was 1 inch or larger , lasted more than a few minutes, or you see dents in gutters/metal, shingles on the ground, or water spots inside, schedule a professional inspection.

Simple HTML hail size / damage table

html

<table>
  <thead>
    <tr>
      <th>Hail size</th>
      <th>Approx. diameter</th>
      <th>Typical roof impact</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Pea</td>
      <td>0.25 inch</td>
      <td>Damage unlikely; minor scuffs or small dings possible on softer materials. [web:1][web:9]</td>
    </tr>
    <tr>
      <td>Penny / Nickel</td>
      <td>0.75–0.88 inch</td>
      <td>Can cause granule loss and minor damage on older or low‑quality roofs. [web:1][web:3][web:7]</td>
    </tr>
    <tr>
      <td>Quarter</td>
      <td>1.0 inch</td>
      <td>Widely recognized damage threshold; can crack shingles and dent metal. [web:1][web:3][web:7][web:9]</td>
    </tr>
    <tr>
      <td>Half dollar</td>
      <td>1.25 inches</td>
      <td>Likely to crack shingles and damage vents, flashing, and older roofs. [web:1][web:3][web:5]</td>
    </tr>
    <tr>
      <td>Ping‑pong ball</td>
      <td>1.5 inches</td>
      <td>High risk of torn shingles, heavy granule loss, and dented or punctured metal. [web:1][web:3][web:5][web:9]</td>
    </tr>
    <tr>
      <td>Golf ball</td>
      <td>1.75 inches</td>
      <td>Severe damage likely to most roofing systems; broken tiles and exposed underlayment. [web:1][web:3][web:5][web:9]</td>
    </tr>
    <tr>
      <td>Tennis ball+</td>
      <td>2.5+ inches</td>
      <td>Widespread destruction; many roofs require partial or full replacement. [web:1][web:3][web:5][web:9]</td>
    </tr>
  </tbody>
</table>

TL;DR: For “what size hail damages roofs,” the practical answer is: around 1 inch is where you should start worrying, and 1.5–1.75 inches and larger is where serious, often insurance‑claim‑level damage becomes very likely.

Information gathered from public forums or data available on the internet and portrayed here.