Roof Repair or Replace Calculator

Run both 10-year paths on the numbers: a 20-year-old architectural roof with 10% damage prices out at about $4,537 to keep repairing (patch now, odds-weighted follow-ups, plus the replacement you still need around year 5), versus $4,200 to replace now and reset to a full 25-year life. That's the crossover zone — with any second issue (a second leak area, brittle shingles, a past-due repair) replacement wins. At 15 years old the same roof still favors repair by about $1,424.

It's the roofing industry's rule of thumb: once a repair quote exceeds about 25% of the cost of full replacement, replacement usually wins, because section work prices worse per square than production re-roofing (our models: $575/sq to re-shingle a damaged arch-shingle section vs $500/sq to re-roof over it). For context, Fixr puts the average replacement at $10,000 and average repairs at just $1,150 — most ordinary repairs pass the test easily. The calculator flags this rule the moment a quote crosses the line.

Value = fraction of life remaining × replacement cost — the same actual-cash-value proration insurance adjusters apply to older roofs. The benchmark here: a 15-year-old architectural roof (40% of a 25-year life left) on a $10,500 replacement is "worth" about $4,200. A repair cheaper than that figure buys more service than it costs; a repair above it means you're paying more than the roof's remaining life is worth — the money usually belongs in a replacement fund instead.

Partly, and the payoff is lumpy on purpose. Fixr's 2026 data puts replacement ROI at 60–70% — roughly $6,000–$7,000 of added value on the average $10,000 job — but the bigger lever is deal flow: buyers' carriers increasingly balk at roofs past ~20 years, which can cost a sale outright rather than just a discount, while a documented recent replacement typically negotiates away more than it cost. If you're selling within a year or two and the roof passes inspection with a repair, take the repair path this calculator prices and disclose the remaining life — replacing purely for resale rarely returns its full cost. The exception is a roof that fails the buyer's insurance inspection: then replacement is the price of selling at all.

Often yes upfront — Fixr notes an overlay saves the ~$50-per-square tear-off and disposal where local codes allow it. The trade-offs are exactly what this calculator can't see: overlays hide decking rot, add weight, run hotter, and make the next replacement pricier (stripping two layers can hit $150/square, per Fixr). An overlay on a roof that's already past ~75% of its life just moves the replacement date — run this tool with the real remaining life, not the sales pitch.

Angi's lifespan data (via NerdWallet, 2026): asphalt shingles 10–20 years, wood shakes 30–50, metal 50–75, clay/concrete tile 50–100, slate 125–200. This tool models 3-tab at 18 years, architectural at 25 (Fixr's 20–30 window for standard asphalt), metal at 55, tile at 60, slate at a conservative 125, and flat membranes at 20. Real-world life swings on ventilation, tree cover, hail belt location and installation quality — a roofer's inspection ($125–$325 per Bob Vila) beats any table.

Only for sudden perils — hail, wind-lifted shingles, a fallen limb — and increasingly on an actual-cash-value basis for older roofs: they pay the prorated value, not the full replacement, which is precisely the proration math this tool uses. Age-related wear is excluded, and carriers now inspect or surcharge roofs past ~20 years. Before you claim, get the repair quote first: a $900 repair claim can cost more in premium increases than it returns, while a genuine storm claim can flip this calculator's verdict to replace overnight.

Four places to look, in order of reliability. First, your city or county building department — roofing jobs are permitted almost everywhere, so the replacement date is on file with the final inspection card or permit history. Second, your closing paperwork: the seller's disclosure and inspector's report usually state the roof's age or remaining life. Third, the shingles themselves — some manufacturers stamp a production date or code on the back of the tabs you can read by lifting an edge. Fourth, the layer count: two layers of shingles means the top layer dates from the last overlay, so the roof is at least as old as that job. When the sources disagree, believe the shingles — this calculator's age input should be the covering's age, not the house's, and every proration and verdict above scales with it.