How to calculate it yourself
Cost-per-year = (initial cost + replacement costs over the period) ÷ years. Metal: $19,000 ÷ 60 years = $317/yr. Asphalt: ($11,500 × 2 cycles) ÷ 50 years = $460/yr. Add metal energy savings ($150/yr typical) and the gap widens by another $7,500 over 50 years.
Common scenarios
Owner-occupied, plan to stay long-term
Metal is the math winner. Lower lifetime cost, better insulation, no replacement headache for 50+ years. The only reason to skip is if HOA forbids metal (some traditional neighborhoods) or if the architectural style demands a specific look.
Selling within 5-10 years
Asphalt is the right call. You will not capture the metal premium in resale; appraisers add only $5,000-12,000 for a metal roof on a typical home. Spend the saved $5,000-10,000 on other improvements with better ROI.
Hail or hurricane zone
Metal almost always wins. Insurance discounts (5-35% premium reduction in some states) plus actual claim avoidance pay back the up-front cost in 5-10 years on top of the longer lifespan.