Run the numbers. Class 4 shingles typically add $2,000–$4,000 to a full replacement, depending on roof size. Against that: several Alberta insurers offer premium discounts for UL 2218 Class 4 roofs (ask yours for specifics; percentages vary by company), plus you avoid repeated deductibles every time hail returns.
Tile handles hail differently. A Class 3–4 impact-rated concrete tile shrugs off storms that shred asphalt shingles, which is why hail rarely tops the failure list on a tile roof: the flashing, ridge mortar and underlayment go first. If that describes your house, start with concrete tile roof repair instead.
And it returns. Calgary sits in hail alley, the corridor running from Calgary through Airdrie, Cochrane, and Chestermere, where summer storms strike multiple times per season. The June 2020 Calgary hailstorm caused roughly $1.4 billion in insured damage, one of the costliest natural disasters in Canadian history. We repaired roofs across northeast Calgary for months afterward. Standard shingles failed; Class 4 roofs largely held. That's the whole case.