Squares to Square Feet Calculator
Convert roofing squares and square feet both ways. One square = 100 ft²—pure unit math.
Quick answer
One roofing square equals 100 square feet. Multiply squares by 100 to get square feet (18 squares = 1,800 sq ft), or divide square feet by 100 to get squares (2,450 sq ft = 24.5 squares). Suppliers price shingles and labor by the square, so this is the first conversion you need before ordering.
Convert roofing squares and square feet
One roofing square = 100 ft². This tool only converts units—no bundles or pitch.
Conversion result
Enter a value and click Convert units.
Reviewed by Mason Rivera, Founder & Estimation LeadHow to Calculate Squares To Square Feet Calculator Manually
Step 1: Start with Verified Roof Dimensions
Measure ridge length, eave length, and the horizontal run from ridge to eave on each plane. Never use floor plan area as a proxy for roof surface—they differ by the slope factor and overhang.
Step 2: Apply the Slope Factor to Each Plane
For each rectangular roof section: sloped area = (ridge/eave length) × horizontal depth × slope factor. Slope factor for 6/12 = 1.118; for 8/12 = 1.202; for 12/12 = 1.414.
Step 3: Sum All Planes and Convert to Squares
Add sloped areas from every facet. Divide total ft² by 100 to get roofing squares. A 2,400 ft² sloped roof = 24 squares. This is the number contractors use to price labor and materials.
Step 4: Add Waste Before Converting to Product Units
Simple gable roofs: 5–8% waste. Hip or cut-up roofs: 10–15%. Multiply sloped ft² by (1 + waste%) then divide by coverage per bundle, roll, or panel to get order quantities.
Step 5: Double-Check Against Field Measure Before Ordering
Planning tools give planning numbers. Walk the roof or use a trusted aerial measurement before submitting a material order. A 5% error on a 30-square job = 1.5 squares of material waste.
Squares To Square Feet Calculator Formulas
- Slope factor = √(1 + (rise ÷ run)²) [e.g. 6/12 pitch: √(1 + 0.25) = 1.118]
- Sloped area = Plan footprint ft² × Slope factor
- Order quantity = ceil(Sloped area × (1 + Waste %) ÷ Unit coverage) [bundles, rolls, or panels]
Use this as a planning starting point. Complex roofs with mixed pitches, dormers, or stepped outlines need individual plane-by-plane takeoffs for accurate ordering.
Roofing Squares to Square Feet: How They Convert on Real Jobs
Why 100 ft² per square exists
Roofing squares bundle large areas into a single trade unit so crews and distributors can quote faster than quoting raw ft² alone.
Bid review without calculator mistakes
When one line shows squares and another shows ft², convert before you compare dollars per unit—otherwise you misread value by 100×.
Frequently Asked Questions — Squares to Square Feet Calculator
Unit conversion only—bundles use separate tools.
How many square feet are in a roofing square?+
One roofing square equals 100 ft² of roof surface.
How do I convert squares to ft²?+
Multiply squares by 100. Example: 18.2 squares → 1,820 ft².
How do I convert roof ft² to squares?+
Divide roof surface ft² by 100. Example: 2,450 ft² → 24.5 squares.
Is this the same as bundle coverage?+
No. Bundle coverage is ft² per bundle from the manufacturer. Squares only convert 100 ft² units.
Why do quotes mix squares and ft²?+
Trades use squares; some suppliers quote in ft². Converting keeps you aligned with both.
Does this tool include pitch?+
No. Enter the roof surface area or squares you already trust from a takeoff or calculator.
What about metric?+
Results show m² as a reference from the same roof ft².
Where do I get bundles from here?+
Use the roofing square calculator or shingle bundle planner after you lock ft² or squares.