RoofTally

How many roof tiles per m²? Tiles per square metre by type (Marley, Redland, plain clay, slate)

9.7 to 60 roof tiles per m²: large interlocking concrete tiles such as Marley Modern take 9.9 per m² at a 345 mm gauge, Redland 49 17.7, natural slate 500 x 250 mm 20 and plain clay tiles 60 at a 100 mm gauge (manufacturer data sheets, read 2026-09-20). Tiles to order = m² of roof x tiles per m² x (1 + 10% waste), rounded up: 100 m² of Marley Modern is 990 tiles laid and 1,089 to order.

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Roof tiles per m² by type (data sheet figures)

Tiles per m² is the covering capacity printed on the data sheet for a batten gauge: the gauge is the spacing of the battens up the slope, and a wider gauge means fewer tiles. 4 of the 7 data sheets print a second figure: the count at a 100 mm headlap, used on low pitches, or the count at the wider gauge allowed from a steeper pitch (Redland 49 from 30°). Battens per m² = 1000 / gauge in mm. All 7 figures below were read on 2026-09-20; the sources are listed at the end.

Roof tiles per m², gauge, second data sheet figure and battens per m² by tile type (data sheets read 2026-09-20)
TileMaterialTiles per m²Gauge (mm)Second figureBatten m per m²
Marley Modern (concrete interlocking)Concrete9.934510.7 at 100 mm headlap2.9
Marley Mendip (concrete double pantile)Concrete9.734510.5 at 100 mm headlap2.9
Marley Ludlow Plus (concrete interlocking)Concrete15.731217.1 at 100 mm headlap3.21
Redland 49 (BMI, concrete interlocking)Concrete17.728216.3 at 307 mm from 30°3.55
Redland Grovebury (BMI, concrete interlocking)Concrete9.7343—2.92
Plain clay tile 265 x 165 mm (Marley Acme, 100 mm gauge)Clay60100—10
Natural slate 500 x 250 mm (100 mm headlap)Slate20200—5

How many roof tiles for 50, 100, 150 m²

Tiles laid = m² of roof x tiles per m², rounded up; tiles to order add 10% for cuts and breakages (a rule of thumb from IKO's roof measuring guide, not a tile manufacturer figure, read 2026-09-20), and the battens are the m² x (1000 / gauge) with the same waste, rounded up to the metre. Whether you ask how many roof tiles per sqm, per sq metre or for the whole roof, the arithmetic is the same: the figures below are computed with the calculator's own code and match the UK tiling cost guide.

Tiles laid / tiles to order at 10% waste for 50 m², 100 m², 150 m² of roof, and battens for 100 m², by tile type
TilePer m²50 m² laid / order100 m² laid / order150 m² laid / orderBattens, 100 m² (m)
Marley Modern (concrete interlocking)9.9495 / 545990 / 1,0891,485 / 1,634319
Marley Mendip (concrete double pantile)9.7485 / 534970 / 1,0671,455 / 1,601319
Marley Ludlow Plus (concrete interlocking)15.7785 / 8641,570 / 1,7272,355 / 2,591353
Redland 49 (BMI, concrete interlocking)17.7885 / 9741,770 / 1,9472,655 / 2,921391
Redland Grovebury (BMI, concrete interlocking)9.7485 / 534970 / 1,0671,455 / 1,601321
Plain clay tile 265 x 165 mm (Marley Acme, 100 mm gauge)603,000 / 3,3006,000 / 6,6009,000 / 9,9001,100
Natural slate 500 x 250 mm (100 mm headlap)201,000 / 1,1002,000 / 2,2003,000 / 3,300550

From the roof to the count: a 12 x 9 m house

The m² is the roof surface, not the floor: plan area (walls plus overhang) x the pitch multiplier, the square root of 1 + (rise / run)². The calculator's starting roof, a 12 x 9 m gable at 26.6° (6:12), has 108 m² of plan and 120.7 m² of roof. The roof area in m² guide has the chart for other footprints and pitches, and the roof pitch guide turns degrees into the multiplier.

The 12 x 9 m gable at 26.6° (120.7 m² of roof) in one tile per material: tiles at 10% waste, battens and ridge tiles
TileTiles per m²TilesBattens (m)Ridge tiles
Marley Modern (concrete interlocking)9.91,31538527
Plain clay tile 265 x 165 mm (Marley Acme, 100 mm gauge)607,9701,32927
Natural slate 500 x 250 mm (100 mm headlap)202,65766527

Why the gauge and the headlap change the figure

The headlap is the overlap between courses. On single-lap interlocking tiles such as Marley Modern and Redland 49 each course overlaps the one directly below it; on double-lap plain tiles and slates it is the overlap over the course two below. Either way, a larger headlap closes the gauge and raises the count. Marley quotes Modern at 9.9 per m² with a 75 mm headlap and 10.7 at 100 mm (Marley, Modern interlocking concrete roof tile, technical specification, read 2026-09-20), the larger lap being for lower pitches. BMI ties Redland 49 to the pitch instead: 17.7 per m² at 282 mm below 30° and 16.3 at 307 mm from 30° (BMI Group, Redland 49 tile product page, pitched roof characteristics, read 2026-09-20). For slates the gauge is (slate length − headlap) / 2: (500 − 100) / 2 = 200 mm for a 500 x 250 slate at 100 mm headlap (Roofing Slate Direct, "Required Slate Quantity", read 2026-09-20), and a wetter or windier site needs more headlap, so more slates. The minimum pitch on each data sheet decides which line applies to your roof. Per-model charts with the gauge and the order for each roof size: Marley Modern tiles per m² and Redland 49 tiles per m².

Work it out for your roof

Open the roof tile calculator, pick the tile under Tile type and type each roof section as length, width, overhang and pitch: the tiles per m² and the gauge load from the data sheet and stay editable, and the tool adds the battens, the ridge and hip tiles and, with your price per tile, the tile cost. For the £ per m² of the tiles and the supplied-and-fitted cost by material, the UK tiling cost guide uses the same counts.

Sources

Frequently asked questions

How many roof tiles per square metre?
9.7 to 60, depending on the tile: interlocking concrete tiles 9.7 to 17.7 per m² (Marley Modern 9.9, Redland 49 17.7), natural slate 500 x 250 mm 20, plain clay tiles 60. Each figure is the covering capacity on the manufacturer or merchant data sheet at the gauge given in the table (Marley, Modern interlocking concrete roof tile, technical specification, read 2026-09-20; BMI Group, Redland 49 tile product page, pitched roof characteristics, read 2026-09-20).
How many roof tiles per sqm for plain tiles?
60 per m² for a 265 x 165 mm plain tile at a 100 mm gauge (Marley, Acme Single Camber clay plain tile, technical specification, read 2026-09-20). Plain tiles are double-lapped, every course covering two below it, which is why the count is about 6 times that of a large interlocking tile such as Marley Modern. 100 m² takes 6,000 tiles laid and 6,600 to order with 10% waste.
How many Marley Modern tiles per m²?
9.9 at a 345 mm gauge and 75 mm headlap, 10.7 at 100 mm headlap (Marley, Modern interlocking concrete roof tile, technical specification, read 2026-09-20). 100 m² is 990 tiles laid, 1,089 to order with 10% waste.
How many Redland 49 tiles per m²?
17.7 at the 282 mm gauge used below 30°, and 16.3 at 307 mm from 30° (BMI Group, Redland 49 tile product page, pitched roof characteristics, read 2026-09-20). 100 m² at the lower pitch is 1,770 tiles laid and 1,947 to order.
How many slates per m²?
20 for 500 x 250 mm slates at 100 mm headlap (Roofing Slate Direct, "Required Slate Quantity", read 2026-09-20), gauge (500 − 100) / 2 = 200 mm. A smaller slate or a larger headlap for an exposed site raises the count; read it from the merchant coverage table for your size. 100 m² is 2,000 slates laid, 2,200 to order.
How many roof tiles do I need for 100 m²?
Laid, then to order with 10% waste: Marley Modern (concrete interlocking) 990 / 1,089; Marley Mendip (concrete double pantile) 970 / 1,067; Marley Ludlow Plus (concrete interlocking) 1,570 / 1,727; Redland 49 (BMI, concrete interlocking) 1,770 / 1,947; Redland Grovebury (BMI, concrete interlocking) 970 / 1,067; Plain clay tile 265 x 165 mm (Marley Acme, 100 mm gauge) 6,000 / 6,600; Natural slate 500 x 250 mm (100 mm headlap) 2,000 / 2,200. The 100 m² is the roof surface (plan area x the pitch multiplier), not the floor area of the house.
How many tiles per m2 roof with hips and valleys?
The same tiles per m²: the coverage is a property of the tile and the gauge, not of the roof shape. What changes is the waste: the calculator starts at 10% (a rule of thumb from IKO's roof measuring guide, not a tile manufacturer figure, read 2026-09-20) and the same rule of thumb gives up to 15% for hips and valleys (IKO, Blueprint for Roofing, read 2026-09-20), because every hip and valley is a line of cut tiles. Hips also take hip tiles, which the calculator counts with the ridge.
How many roof tiles in a square (US)?
A roofing square is 100 sq ft, which is 9.29 m², so multiply the tiles-per-m² figure by 9.29: about 92 Marley Modern or 557 plain clay tiles per square. UK manufacturers quote coverage per m² only; the calculator works in m² in UK mode.

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Last updated 2026-10-03. Planning quantities from manufacturer coverage figures and published cost ranges, each with its source and date: measure the roof and follow the product data sheet. Not a structural assessment.