✅ Mathematically Verified Formulas

Complete All-in-One Tool for Professional Roofing Contractors • Accurate Mathematical Formulas

Perfect for Gable, Hip, Mansard, Gambrel, and Shed Roofs • No Other Calculator Needed

✅ Accurate Formulas
✅ All Roof Types
✅ Complete Material List
✅ History & Export
✅ Mobile Friendly
✅ Print Ready
Note: This version has mathematically verified formulas. All calculations have been tested for accuracy.

🛠️ Roof Measurement Input

Please enter a calculation name

🏠 Select Roof Type:

🔺 Gable Roof
🔶 Hip Roof
🏛️ Mansard Roof
🌾 Gambrel Roof
⛺ Shed Roof
Measure side to side at the base
Width must be between 1 and 1000 feet
Measure front to back at the base
Length must be between 1 and 1000 feet
Common: 4:12 (normal), 6:12 (steep), 12:12 (very steep)
Pitch must be between 1 and 24
Standard overhang is 0.5 to 1.5 feet (6 to 18 inches)
Overhang must be between 0 and 5 feet
10-15% is typical for waste and cutting
Waste must be between 0% and 50%

💡 Quick Tips:

• Always measure building from outside wall to outside wall

• Pitch is measured as inches of rise per 12 inches of run

• Save calculations with customer names for easy reference

📊 Calculation History

No calculations yet. Your calculation history will appear here automatically.

📋 Results Will Appear Here

Enter your roof measurements on the left and click "CALCULATE" to see detailed results here.

📐

Ready to Calculate Your Roof

Fill out the form to get accurate calculations for:

  • ✅ Exact material quantities
  • ✅ Accurate rafter lengths
  • ✅ Complete shopping list
  • ✅ Waste calculations
  • ✅ Printable estimates
Mathematically Verified: All formulas have been tested and corrected for accuracy.

📚 How to Use This Calculator (Simple Guide)

1 Pick Your Roof Type

Click on the roof picture that looks like your roof. We got gable, hip, mansard, gambrel, shed roofs. Most houses are gable or hip roofs. If you not sure, pick gable.

2 Measure Your Building

Get building width and length in feet. Width is side to side. Length is front to back. You can use tape measure or laser measure. Measure from outside wall to outside wall. Put numbers in the boxes.

3 Find Roof Pitch

Pitch is how steep roof is. If you don't know pitch, guess 4:12 (that's normal pitch). Steep roof maybe 6:12 or 8:12. Flat roof is 2:12. Put number in pitch box. For mansard and gambrel roofs, you need two pitches - lower and upper.

4 Add Overhang

Overhang is roof part that sticks out over wall. Usually 0.5 to 1 foot. If you not sure, use 0.5 feet (6 inches).

5 Waste Percentage

When you cut shingles, some get wasted. Also for mistakes. Keep it at 10% for normal jobs. If complicated roof with many cuts, use 15%.

6 Click Calculate

Press the big blue CALCULATE button. Wait one second. Then see all results on right side. You get everything you need to buy.

7 Print or Save

You can print the results or save to computer. History saves automatically so you can come back later and see your old calculations. Export to CSV for your records.

💡 Pro Tips for Contractors:

• Always measure twice before calculating

• Add 2-3 extra bundles for safety on complex roofs

• Save calculations with client names for easy reference

• Export to CSV for your job records and billing

• Use print function for customer estimates and proposals

• Check local building codes for special requirements

✅ This Version Features:

• Mathematically accurate formulas (all bugs fixed)

• Correct hip roof area calculation

• Proper mansard and gambrel calculations

• Accurate waste percentage calculations

• Complete materials list with quantities