Roof Tile Calculator
Reviewed by the My Roof Pitch editorial team · Updated · Free, no sign-up, works offline after first load
Tile quantity is sloped roof area divided by the tile coverage per piece, plus waste. A 2,000 sq ft roof covered with 13×16 inch tiles at a 1.6 ft² exposure needs about 1,470 tiles before waste.
Your measurements
Enter the values you know — results update live.
Plan-view area including overhangs.
Tiles need at least 2.5:12 under IRC R905.3.
The width that is not overlapped by the next tile.
The length that is not overlapped by the course above.
10% for simple gables; 18% or more for hips and valleys.
Analysis
Live results from your measurements.
Show the working
- Sloped area:
1,800 × 1.118= 2,012 sq ft - Tile exposure:
(13 × 16) ÷ 144= 1.444 sq ft - Tiles before waste:
2,012 ÷ 1.444= 1,393 - With waste:
1,393 × 1.12= 1561
What this calculator does
Clay, concrete and Spanish tiles are sold by the piece or by the bundle, and each piece covers only its exposed footprint after overlaps. The head lap and side lap vary by profile and manufacturer, so the calculator lets you enter the exposed width and length rather than guessing a coverage factor. Because tile roofs are heavy and brittle, waste is higher than for shingles — hips, valleys and ridge cuts break pieces, and colour lots must match across the job. The IRC also sets a 2.5:12 minimum pitch for clay and concrete tile, which is steeper than many shingle minimums.
How to use it
- Measure the building footprint including overhangs.
- Apply the pitch multiplier to get the true sloped roof area.
- Enter the tile's exposed width and length from the manufacturer's data sheet.
- Divide the sloped area by the net tile exposure to get the piece count.
- Add a waste allowance of 12% to 20% depending on roof complexity.
- Convert to bundles if your supplier sells them that way.
The formula
Sloped roof area
sloped area = footprint × pitch multiplier
Tiles cover the sloped surface, not the plan view.
Tile exposure
tile exposure = (exposed width × exposed length) / 144
Converts inches to square feet of actual coverage per tile.
Tile count
tiles = ceil((sloped area / tile exposure) × (1 + waste))
Rounds up to whole tiles and includes waste.
Worked example
A 2,200 sq ft footprint, 7:12 hip roof, 13×16 inch tile exposure, 15% waste.
- Multiplier for 7:12: 1.1577
- Sloped area: 2,200 × 1.1577 = 2,547 sq ft
- Tile exposure: 13 × 16 ÷ 144 = 1.444 sq ft
- Tiles: 2,547 ÷ 1.444 × 1.15 = 2,027
Order about 2,030 tiles, plus underlayment, battens and ridge/hip pieces.
Reference chart
| Exposure (in) | Net coverage | Tiles per 1,000 sq ft | With 12% waste |
|---|---|---|---|
| 10 × 12 | 0.833 | 1200 | 1344 |
| 13 × 16 | 1.444 | 693 | 776 |
| 14 × 18 | 1.75 | 571 | 640 |
| 16 × 20 | 2.222 | 450 | 504 |
Tile type weights and typical exposures
| Tile type | Weight per sq ft | Typical exposure | Service life |
|---|---|---|---|
| Clay mission | 8–10 lb | 13 × 16 in | 50–100 years |
| Concrete flat | 9–12 lb | 14 × 18 in | 30–50 years |
| Spanish S-tile | 8–11 lb | 10 × 16 in | 50–75 years |
| Slate tile | 8–10 lb | 10 × 12 in | 75–150 years |
Common mistakes
- Using the full tile width and length instead of the exposed dimensions.
- Forgetting the 2.5:12 minimum pitch requirement for clay and concrete tile.
- Underestimating waste on a hip roof where every corner needs cuts.
- Ordering tiles from different lots, which can vary in colour and profile.
- Ignoring the extra weight; tile roofs often need reinforced framing.
Assumptions and limits
- Tiles are laid with uniform head and side lap as specified by the manufacturer.
- Ridge, hip and starter tiles are ordered separately.
- The roof structure can support the dead load of the chosen tile.
- Minimum pitch meets IRC R905.3 for clay or concrete tile.
Frequently asked questions
How many roof tiles do I need?
Divide the sloped roof area by the net exposed area of one tile, then add 12% to 20% waste. A 2,000 sq ft roof with 13×16 inch tiles needs about 1,690 tiles with 15% waste.
What is the minimum pitch for roof tiles?
Clay and concrete tile generally requires a 2.5:12 pitch under the IRC. Some profiles and manufacturer systems are approved lower, but that needs a specific evaluation report.
How much waste should I allow for roof tiles?
10% for a simple gable, 15% for a typical hip, and 18% to 20% if the roof has many valleys, dormers or odd angles.
How heavy are roof tiles?
Clay and concrete tiles weigh 8 to 12 pounds per square foot of roof area, roughly 800 to 1,200 pounds per square. That is two to four times the weight of asphalt shingles.
Can I install roof tiles over shingles?
No. Tile needs a sound deck, proper underlayment, and usually horizontal battens or a direct-deck attachment system. Shingles add too much weight and unevenness.
How long do clay and concrete roof tiles last?
Clay tiles often last 50 to 100 years, while concrete tiles typically last 30 to 50 years. Both outperform asphalt shingles but require a stronger roof structure.
Related guides
Last updated 2026-08-05. Results are estimates for planning and are not a substitute for a licensed engineer or local code review.