Roof Tile Calculator
Roof dimensions
Rise in inches per 12 inches of run.
Roof tiles to buy
1,329 tiles
- Footprint
- 1200 sq ft
- Pitch multiplier
- 1.118
- Actual roof area
- 1341.6 sq ft
- Roofing squares
- 13.4
- Battens (linear ft)
- 1,680 ft
- Estimated tile weight
- 12,074 lbs
Confirm the exposure and tiles-per-square figure on your specific tile's data sheet.
Roof pitch multiplier table
| Pitch | Multiplier | Roof area for a 1,200 sq ft footprint |
|---|---|---|
| 3:12 | 1.031 | 1,237 sq ft |
| 4:12 | 1.054 | 1,265 sq ft |
| 6:12 | 1.118 | 1,342 sq ft |
| 8:12 | 1.202 | 1,442 sq ft |
| 10:12 | 1.302 | 1,562 sq ft |
| 12:12 | 1.414 | 1,697 sq ft |
Tiles per square by type
| Tile type | Tiles per square | Weight per square | Typical life |
|---|---|---|---|
| Concrete tile | 90 | 900 lbs | 50+ years |
| Clay barrel tile | 100 | 850 lbs | 75+ years |
| Slate | 170 | 800 lbs | 100 years |
| Flat interlocking | 80 | 750 lbs | 50 years |
Cutting and safety gear
ZORUNNA 2Pcs 4.5" Diamond Blade for Angle Grinder, Tile Saw Blades | Clean Cuts with Less Chipping, Less-Wobble Core, Smooth Finish for Porcelain Ceramic Granite Tile Marble, Wet/Dry Cuts
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DEWALT Diamond Blade for Masonry, Dry Cutting, Continuous Rim, 7/8-Inch Arbor, 4-1/2-Inch (DW4725)
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ZORUNNA 5Pcs 4.5" Diamond Saw Blades, Tile Cutting Blade for Angle Grinder | Clean Cuts with Less Chipping, Smooth Finish for Porcelain Ceramic Granite Tile Marble, Less-Wobble Core, Wet/Dry Cuts
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EZARC 4-1/2" Super Thin Diamond Tile Blade, 7/8"-20mm-5/8 Arbor, 2-Pack | Diamond Saw Blades for Angle Grinder, Smooth Cuts,Chip-Free,Minimal Breakage,for Porcelain,Ceramic, Marble,Wet or Dry Cuts
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4-1/2 inch Tile Cutter Diamond Saw Blade for Angle Grinder Porcelain Ceramic Glass Marble Cutting Tools Grinding disc (3pcs)
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4-1/2 Inch Segmented Diamond Saw Blades 2-Pack, Tile Cutter Blades | Diamond Cutting Wheel for Angle Grinder, for Cutting Stone Marble Granite Concrete Brick, 7/8’’-20mm Arbor
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Do this math on the job site — in the free app
Smart Tile Calculator for Android: offline, in your pocket, no ads. iPhone version coming soon.
Tools the pros use for this job
Diamond Blade
ZORUNNA 2Pcs 4.5" Diamond Blade for Angle Grinder, Tile Saw Blades | Clean Cuts with Less Chipping, Less-Wobble Core, Smooth Finish for Porcelain Ceramic Granite Tile Marble, Wet/Dry Cuts
Check price on AmazonCutting concrete and clay roof tile takes a diamond wheel, not a snap cutter.
Safety Glasses & Knee Pads
Sponsored Ad - Salfboy Ansi Z87.1 Certified Safety Glasses, Bulk Protection Glasses | Clear Safety Glasses for Men, with Soft Silicone Legs, Scratch Resistant, Impact Resistance, for Construction, Woodworking
Check price on AmazonTile dust and roof battens are hard on eyes and knees alike.
Laser Distance Measure
Tile Tools Stainless Steel Square Notch Trowel Set Plus Rubber Grout Float and Grout Sponge for Tiling Installation Grouting
Check price on AmazonMeasure eave-to-ridge from the ground instead of walking the roof.
Paid links — we may earn a commission at no extra cost to you.
How this calculator works
Roof area = footprint × pitch multiplier. A 40 ft × 30 ft house is 1,200 sq ft of footprint; at a 6:12 pitch the multiplier is 1.118, so the roof surface is 1,342 sq ft, or 13.4 squares.
Tile counts are quoted per square (100 sq ft). Concrete tile averages about 90 tiles per square, clay barrel tile around 100, and slate 170 depending on exposure. Add 10% waste for hips, valleys and breakage — 15% on a complex roof with multiple valleys.
Weight is the constraint. Concrete and clay tile weigh 750–950 lbs per square, three to four times an asphalt shingle roof. Any re-roof from shingle to tile needs a structural engineer to confirm the framing can take it.
Doing a full roofing project? Our sister site Smart Roofing Calculator has the full roofing suite — shingles, underlayment, pitch, plywood and nails. For floor tile, start with the tile quantity calculator or the patio tile calculator. Ordering roof tile follows the same waste rules as floor tile — hips, valleys and rakes all end in cuts — so check the tile waste factor guide before you place the order.
Frequently asked questions
How many roof tiles do I need per square?
About 90 concrete tiles, 100 clay barrel tiles, or 170 slates per 100 sq ft square, depending on the exposure the manufacturer specifies.
How do I calculate roof area from the ground?
Measure the building footprint, then multiply by the pitch multiplier for your roof slope — 1.054 for 4:12, 1.118 for 6:12, 1.202 for 8:12.
How much does a tile roof weigh?
Concrete tile runs 900 lbs per square and clay about 850 lbs, versus roughly 250 lbs for architectural asphalt shingles. Framing must be checked before switching.
How much waste should I allow for roof tile?
10% on a simple gable roof, 15% on a hip roof with valleys, dormers or skylights.
Related calculators
- Tile Quantity CalculatorHow many tiles you need for any room, wall, or floor — with waste.
- Patio & Outdoor Tile CalculatorOutdoor-rated tile, mortar, and drainage gaps for patios.
- Tile Weight CalculatorTotal tile weight for delivery, upstairs floors, and structure.
- Tile Cost EstimatorTotal project cost: tile, grout, mortar, trim, and labor.
Guides worth reading next
- How to Measure a Room for Tile (Step by Step)Measure any room for floor or wall tile: handle closets and alcoves, convert inches to decimals, subtract fixtures, and add the right waste percentage.
- Choosing the Right Tile Size for Your RoomHow tile size changes a room: when 12×24 beats 4×4, why small rooms can take large tile, grout line math, and the flatness rule for big formats.
- Sanded vs Unsanded vs Epoxy Grout: Which One Do You Need?Grout types explained by joint width and location: when sand scratches tile, why epoxy wins in showers, and how much of each type a bag actually covers.