Crunch the numbers before you build.
Estimate shingles, underlayment, and total material costs by roof size and pitch. Know your numbers before the first call.
By BuildCrunch Team · Last updated July 17, 2026
A 1,200 sq ft home footprint with a 4/12 pitch and architectural shingles needs about 14.5 roofing squares (59 bundles) — roughly $1,891 in material cost, before labor.
4/12 pitch = 5.4% more area than flat
We multiply your building's footprint (length × width) by a pitch multiplier that accounts for the extra surface area a sloped roof has versus a flat one — a 4/12 pitch adds about 5%, a 12/12 pitch adds about 41%.
We then add your waste factor and divide by 100 to get roofing squares (1 square = 100 sq ft), which drives the bundle, underlayment, and nail counts above.
Get a copy emailed to you, or connect with local pros for a real quote.
Standard 3-tab shingles require 3 bundles per roofing square (100 sq ft). Architectural/dimensional shingles are heavier and require 4 bundles per square. Always buy an extra bundle or two for cuts, waste, and future repairs.
For a typical 2,000 sq ft home, expect $8,000-$15,000 for asphalt shingles, $15,000-$30,000 for metal, and $25,000-$50,000 for tile. Labor accounts for roughly 60% of total cost. Prices vary significantly by region and roof complexity.
Most building codes allow up to 2 layers of asphalt shingles. However, tearing off the old layer lets you inspect the decking for damage and typically extends the life of the new roof. This calculator includes a tear-off cost estimate when you set existing layers above 1.
Steeper roofs have more surface area than flat roofs over the same footprint. A 12/12 pitch has 41% more surface area than a flat roof, meaning 41% more materials. Steep roofs also increase labor costs due to safety equipment requirements.
If damage is localized — a few missing shingles, a small leak around a vent pipe — a repair usually makes sense. If your roof is past 75% of its expected lifespan, has widespread granule loss, or you're seeing leaks in multiple rooms, full replacement is typically more cost-effective than chasing repairs year after year.
3-tab shingles are flat, uniform, and lightweight (about 3 bundles per square) with a 15-20 year lifespan. Architectural shingles are thicker, layered for a dimensional look, weigh more (4 bundles per square), and last 25-30 years. Architectural is now the standard choice for most residential re-roofs — 3-tab is mainly chosen to match an existing older roof or save on upfront cost.