Area Calculator (circle, square, triangle, etc.)

Roof Area & Square Footage Calculator

Units

Roof pitch

Waste / offcuts % (typical 10–15%)

Pitch multiplier: calculated automatically from rise per 12″ run.

Results

Plan area—

Roof surface area (pitch)—

Area incl. waste—

Roofing squares (100 ft²)—

~Bundles of shingles (≈3/bundle per square)—

Rectangle / Multi-Room Calculator

Add rooms (or sections) by length × width. Switch units above to ft or m.

Tip: Use Tab to jump between fields. The plan area updates as you type.

Draw on Map

Draw a polygon around the roof footprint. The plan area will appear in Results and be adjusted by the roof pitch.

Search by Address

Address or postcode

Pan/zoom to the roof and draw a polygon (same tools). You can also paste a full address.

Roof Area & Square Footage Calculator (Free Online Tool)

Measure your roof or floor area in square feet or square metres. Whether you’re planning a new roof, replacing shingles, or estimating flooring, this calculator gives quick and accurate results.

Features of Our Roof Square Footage Calculator

📏 Rectangle & Multi-room measurements (length × width)
🗺️ Draw on map for precise polygon-based roof area
🏠 Search by address or postcode for easy navigation
⚡ Roof pitch adjustment with automatic multiplier
🗑️ Waste factor setting (offcuts & overlap)
📊 Results in ft², m², roofing squares & shingle bundles

How the Roof Area Calculator Works

Our free Roof Area & Square Footage Calculator is designed to make measuring easy. You can calculate in three different ways, depending on your project:

1. Rectangle / Multi-Room Entry

Enter the length and width of each room or roof section.
Add multiple rooms or sections if your building isn’t a simple rectangle.
The calculator totals them automatically.

👉 Best for: Flooring, simple flat roofs, small home projects.

2. Draw on the Map

Use the interactive map to outline your roof shape.
The tool calculates the polygon area instantly in square feet or metres.
Adjust the roof pitch to account for slope and add a waste factor (extra material for overlaps and cuts).

👉 Best for: Complex roofs, larger buildings, outdoor spaces.

3. Search by Address

Type in your address or postcode.
Zoom into your property on the satellite map.
Draw around the roof footprint and get an instant measurement.

👉 Best for: Quick roof size check without climbing ladders or using tape measures.

Automatic Adjustments

Roof pitch multiplier: Calculates slope area vs flat area.
Waste factor: Adds extra coverage (typically 10–15%) to avoid under-ordering materials.
Results provided in:
- Square feet (ft²)
- Square metres (m²)
- Roofing squares (100 ft² each)
- Estimated shingle bundles

✅ In just minutes, you’ll know the exact roof or floor size and material estimate—without climbing on the roof or doing manual math.

Why Use a Roof Size Calculator?

Accurate roof measurement saves time, reduces material waste, and prevents costly errors. Contractors, DIY homeowners, and solar installers use roof calculators to:

Estimate shingles, tiles, or roofing sheets
Calculate solar panel coverage area
Plan roof replacement or repairs
Measure flooring, decking, or patio areas

Roof Pitch Adjustment

1 roofing square = 100 ft² of roof surface.
Our calculator also shows the number of squares and bundles (≈3 bundles per square), making it easy to order the right materials.

Roofing Squares & Bundle Estimates

Roof pitch increases actual surface area compared to flat dimensions. Example:

Flat roof = 1.0 multiplier
8/12 pitch = ~1.54 multiplier
Steep 12/12 pitch = ~1.73 multiplier

This tool applies the correct pitch factor automatically.

FAQs – Countdown Timer

Q1: How do I calculate my roof area?
You can measure roof area by entering the length and width of each section or by drawing directly on the map using your address. The calculator adds pitch and waste factors for accuracy.

Q2: What is a roofing square?
One roofing square equals 100 square feet of roof surface. Roofers commonly use squares to estimate shingles and materials.

Q3: Can I calculate roof size by address?
Yes. Enter your address or postcode, zoom into your property on the map, and outline the roof with the polygon tool to get instant measurements.

Q4: Does roof pitch affect material estimates?
Yes. A steeper roof has more surface area than a flat one. Our calculator multiplies your base area by the correct pitch factor.

Q5: Can this be used as a floor calculator?
Absolutely. The rectangle/multi-room feature lets you calculate flooring, tiling, or decking area quickly.