Roof Tile Calculator
Enter each roof slope separately, add ridge and hip lengths, and get a full material breakdown
Roof Slopes
Standard concrete interlocking tile - approx 10 per m². Check the manufacturer's spec sheet for the exact gauge for your pitch.
From the product data sheet - varies by tile size and batten gauge
The centre-to-centre spacing between battens - set by the tile manufacturer
10% is standard; allow 15% for complex roofs with many hips and valleys
Measure along the ridge line and each hip rafter. Leave blank if not applicable.
Add all hip rafter lengths together
Larger battens needed for heavier tiles or rafter spans over 1.8 m.
Standard stock length from your supplier (3.6 m or 4.8 m are most common).
Centre-to-centre spacing of rafters - needed to calculate nails. 600 mm is standard UK.
Galvanised clout nails, 30-40 mm. Two nails per batten per rafter.
Minimum 150mm side lap, 300mm at eaves and ridge
Job Costing
Enter costs in your local currency.
UK Market PricesFills in the material cost fields with current UK market prices. You can review and edit each price before applying.
Results
Total Roof Area
-
m²
Field Tiles
-
inc. waste
Battens
-
linear metres (net)
Batten Lengths
-
lengths to order
Clout Nails
-
boxes
Felt Rolls
-
rolls needed
Slope Breakdown
| Slope | Eaves Length | Rafter Length | Area | Tiles | Battens (lm) |
|---|
🚫 Estimate waste & skip size for this project →
Doing this as a homeowner?
Who do you actually need to hire for this?
Not sure what some of these terms mean?
Browse all →
Frequently Asked Questions
How many roof tiles do I need per square metre?
Concrete interlocking tiles: approximately 9-10 tiles per m². Clay plain tiles (265 x 165 mm): approximately 60 tiles per m² at standard 100 mm gauge. Pantiles: approximately 10-12 per m². Always check the manufacturer's specification - coverage rates vary between products. Add 5-10% for waste and cuts at verges.
What is batten gauge for roof tiles?
Batten gauge is the distance between adjacent batten centres - equal to the exposed face of each tile course. For plain tiles and slates: (tile length - headlap) ÷ 2. For a 265 mm plain tile with 75 mm headlap: (265 - 75) ÷ 2 = 95 mm gauge. For interlocking tiles, the gauge is fixed by the tile design.
What minimum pitch do roof tiles require under UK Building Regulations?
Per BS 5534 and tile manufacturer specs: concrete interlocking tiles minimum 17.5-22.5° depending on exposure. Clay plain tiles minimum 35°. Pantiles minimum 22.5° (low exposure) to 35° (very exposed). Always check your specific tile manufacturer's minimum pitch for your exposure zone.
How many ridge tiles do I need?
Measure total ridge length and divide by ridge tile length (typically 450 mm for half-round ridge). A 6 m ridge needs 6 ÷ 0.45 = 14 ridge tiles (round up). For hip roofs, measure each hip rafter and add to ridge length. Allow 10% extra for cuts at ridge-hip junctions.
What waste allowance should I use for roof tiles?
Simple gable roof: 5% waste. Roofs with hips, valleys, dormers or skylights: 10%. Complex details with many small cuts: 10-15%. Ridge and hip tiles: allow 5% extra for cuts at junctions. Check tiles per pallet to avoid ordering unnecessary whole pallets.
Do I need planning permission to re-tile my roof?
Re-tiling with similar materials is generally permitted development - no planning permission required. Exceptions: Conservation Areas (changes to external appearance may need consent) and Listed Buildings (listed building consent required for any alterations). Planning permission and Building Regulations are separate requirements - check with your local planning authority if in doubt.