How to Measure a Roof for Shingles
Whether you’re getting quotes, ordering materials, or DIYing, accurate roof measurements are essential. Here’s how to measure your roof properly – plus an easier way that doesn’t require a ladder.
Quick Answer
To measure a roof for shingles: (1) Calculate your roof’s square footage, (2) divide by 100 to get “squares,” (3) add 10-15% for waste. A 2,000 sq ft roof = 20 squares + 2-3 squares for waste = 22-23 squares of shingles needed. Or use our free roof report to get measurements instantly.
Two Ways to Measure Your Roof
Method 1: Use Satellite Data (Recommended)
The easiest and safest way to measure your roof is with satellite imagery. Our free roof report tool does this automatically:
- Enter your address
- Get total square footage, pitch, and sections in 60 seconds
- No ladder, no measuring, no math
Why satellite is better
Satellite measurements account for pitch automatically and measure each roof section precisely. Manual measurements often miss sections or miscalculate slope area.
Method 2: Manual Measurement
If you prefer to measure yourself, here’s the process:
Measure your roof’s footprint
Measure the length and width of your house from the ground. Include overhangs (usually 1-2 feet on each side).
Calculate the base area
Multiply length × width. A 40′ × 30′ house = 1,200 sq ft footprint.
Determine your roof pitch
Use a level and tape measure in your attic, or use our pitch calculator.
Apply the pitch multiplier
Multiply footprint by pitch factor: 4/12 = 1.054, 6/12 = 1.118, 8/12 = 1.202, 10/12 = 1.302
Convert to squares and add waste
Divide by 100 to get squares, then add 10-15% for waste (more for complex roofs).
Safety first
Climbing on your roof is dangerous. If you’re not experienced, use ground-level measurements or satellite data instead.
How Much Shingle Waste to Add
Shingles need to be cut at angles, ridges, and edges. The waste factor depends on your roof’s complexity:
| Roof Type | Waste Factor | Example (20 squares) |
|---|---|---|
| Simple gable (2 sections) | 10% | Order 22 squares |
| Standard (4-6 sections) | 12-15% | Order 23 squares |
| Complex (valleys, dormers, hip) | 15-20% | Order 24 squares |
| Very complex (many angles) | 20-25% | Order 25 squares |
Pro tip: Order extra
It’s better to have a few extra bundles than to run short mid-job. Extra shingles can be returned or saved for future repairs.
Skip the Math – Get Your Measurements Free
Enter your address and get satellite-measured roof data in 60 seconds.
Get Free Roof ReportFrequently Asked Questions
How many bundles of shingles per square?
Most architectural shingles require 3 bundles per square (100 sq ft). Some heavier shingles need 4 bundles. Always check the coverage listed on the bundle packaging.
How do I account for steep pitch?
Multiply your footprint area by the pitch factor: 4/12 pitch = ×1.054, 6/12 = ×1.118, 8/12 = ×1.202, 10/12 = ×1.302. This gives you the actual roof surface area. Or use our satellite tool which calculates this automatically.
Should I measure from inside or outside?
Both work. From outside, measure the house footprint and add overhangs (typically 1-2 feet per side). From inside the attic, you can measure rafter length directly but need to account for each roof section.
How accurate do measurements need to be?
Within 5% is acceptable for ordering materials – that’s why you add waste factor. For comparing contractor quotes, you want to be as accurate as possible so you can spot overestimates.