Free Roofing Calculators for Accurate Estimates
Plan a roof like a pro—start with geometry (area, pitch, overhangs), then convert to materials (shingles, nails, plywood, underlayment), finish with water control (drip edge, flashing, vents), and confirm framing. These roof-only calculators speed up takeoffs, budgets, and ordering.
⭐ Quick Picks
Most-used calculators by contractors and DIYers.
🧭 Roof Area, Pitch & Overhang Tools
Start hereNail the geometry first—roof area, pitch/slope, and safe eave/rake overhangs—so every downstream estimate is accurate.
📐 Roof Area Calculator
Estimate total roof surface area with pitch factors—perfect for base takeoffs.
→📏 Pitch Calculator
Find roof pitch and slope factor for accurate coverage conversions and waste.
📈 Roof Slope Calculator
Compute slope %, angle (°), ratio, and slope multipliers—optionally ridge height.
📊 Roof Pitch Chart
Quick reference: angles, slope %, multipliers, and readable 1/12–24/12 diagram.
🪟 Roof Overhang Calculator
Compute eave & rake overhangs, drip edge, starter, soffit area, fascia pieces, and intake vent suggestions for balanced airflow.
🧱 Shingle, Nail & Decking Estimators
Convert geometry to material counts: shingles, nails, plywood, underlayment, ridge caps, and starters.
🧱 Shingles Estimator
Bundles by roof area, exposure, and waste. Supports common shingle types.
🔩 Nail Estimator
Nails per bundle and total fasteners—adjust by exposure and fastener schedule.
🪵 Plywood Estimator
Sheet counts by deck area, panel size, and staggered seam orientation.
📜 Underlayment Roll Estimator
Rolls by coverage and overlap rules (valleys/walls edges auto-allowance).
⛰️ Ridge Cap Estimator
Bundle needs from total ridge/hip footage and profile.
🧵 Starter Strip Estimator
Starter counts for eaves and rakes. Avoids short-course gaps on rakes.
💧 Drip Edge, Flashing & Ventilation
Keep water out where it matters most—edges, valleys, walls, and penetrations. Balance intake and exhaust for a dry attic.
💧 Drip Edge Estimator
Linear feet for eaves and rakes with overlap, including miters at corners.
⚡ Flashing Estimator
Valleys, step flashing, headwalls, sidewalls—adds fastener/waste allowances.
🌊 Valley Estimator
Open/closed valley footage including metal stock or shingle weaving.
🌬️ Roof Vent Estimator
Exhaust/intake balance from attic square footage and pitch—soffit + ridge.
🗑️ Waste Calculator
Add material percentage for cuts, hips/valleys, and complex roof facets.
🏗️ Trusses, Metal & Barn Roof Calculators
Estimate framing members and specialty profiles before committing to a cover system.
🏗️ Roof Truss Calculator
Truss count, chord lengths, truss height, roof area & sheathing by span/pitch.
🧰 Metal Roof Calculator
Panels, trims & flashing, fasteners, labor, and OH&P with seam profile options.
🏚️ Barn Roof (Gambrel) Calculator
Ridge/break heights, rafter lengths, frame counts, roof area & sheathing per bay.
💵 Repair & Cost
Budget realistically for removal, disposal, labor, and service visits.
🧹 Roof Tear-Off Cost
Labor, debris handling & dump fees by layers, access, steepness, and region.
💧 Roof Leak Repair Estimator
Visit fee, labor, materials, trim, moisture mitigation, travel, permits, OH&P, tax.
Want a printable takeoff? Export from each calculator page (PDF/CSV) to share with clients or suppliers.
🧭 How to Use These Roofing Calculators
- 1) Geometry → Run Area, Pitch/Slope, and Overhang first.
- 2) Materials → Convert to shingles, nails, plywood, underlayment, ridge caps, starters.
- 3) Water Control → Size drip edge, flashing, valleys, and vents.
- 4) Framing/Specialty → Check trusses and specialty profiles (metal, gambrel).
❓ Roofing Calculator FAQ
How accurate are the shingle & underlayment estimates?
Results use industry-standard coverage and add recommended waste. For complex hips, valleys, or dormers, increase waste by 5–10%.
Do these tools support metal roofing?
Yes—use the Metal Roof Calculator for panel counts, trims, and fasteners; pair it with pitch/overhang tools for layout.
What pitch should I use if my roof varies?
Measure each major plane. If you must average, pick the steeper section to avoid short-ordering.