How many tiles do I need?

Whole tiles for the common sizes and layouts, worked out at the areas people actually tile. Every figure below came out of the tile calculator, so the table and the tool agree.

Quick answer

For a plain square room with a 3 mm joint, a 10 m² floor takes about 125 tiles at 300 × 300, 63 at 300 × 600 and 32 at 600 × 600, laid straight. Diagonal adds roughly 3–5% on top and herringbone about 6%. Small rooms carry more waste rather than less: the same tile in a 5 m² room runs at 16% waste against 12% in a 50 m² one.

300 × 300 mm tiles with a 3 mm joint, square room, nothing to cut around. Whole tiles including waste.
Floor area	Straight	Diagonal 45°	Herringbone	Waste range
5 m²	64	66	68	16.0–24.0%
10 m²	125	130	133	14.0–22.0%
15 m²	183	192	197	12.0–20.0%
20 m²	244	255	262	12.0–20.0%
25 m²	305	319	327	12.0–20.0%
30 m²	366	383	393	12.0–20.0%
40 m²	488	510	523	12.0–20.0%
50 m²	610	638	654	12.0–20.0%

300 × 600 mm tiles with a 3 mm joint, square room, nothing to cut around. Whole tiles including waste.
Floor area	Straight	Diagonal 45°	Herringbone	Waste range
5 m²	32	34	34	16.0–24.0%
10 m²	63	66	67	14.0–22.0%
15 m²	92	97	99	12.0–20.0%
20 m²	123	129	132	12.0–20.0%
25 m²	154	161	165	12.0–20.0%
30 m²	184	193	198	12.0–20.0%
40 m²	246	257	263	12.0–20.0%
50 m²	307	321	329	12.0–20.0%

600 × 600 mm tiles with a 3 mm joint, square room, nothing to cut around. Whole tiles including waste.
Floor area	Straight	Diagonal 45°	Herringbone	Waste range
5 m²	16	17	18	16.0–24.0%
10 m²	32	33	34	14.0–22.0%
15 m²	47	49	50	12.0–20.0%
20 m²	62	65	67	12.0–20.0%
25 m²	78	81	83	12.0–20.0%
30 m²	93	97	100	12.0–20.0%
40 m²	124	129	133	12.0–20.0%
50 m²	155	161	166	12.0–20.0%

200 × 1200 mm plank tiles with a 3 mm joint, square room, nothing to cut around. Whole tiles including waste.
Floor area	Straight	Diagonal 45°	Herringbone	Waste range
5 m²	24	25	26	16.0–24.0%
10 m²	47	49	50	14.0–22.0%
15 m²	69	72	74	12.0–20.0%
20 m²	92	96	99	12.0–20.0%
25 m²	115	120	123	12.0–20.0%
30 m²	138	144	148	12.0–20.0%
40 m²	184	192	197	12.0–20.0%
50 m²	230	240	246	12.0–20.0%

Why the same floor needs different numbers

Three things are being added, and they stack:

The pattern. A straight grid wastes about 10%, because only the perimeter gets cut. Diagonal wastes about 15% — every edge tile is cut, and the offcuts are triangles that rarely fit anywhere else. Herringbone is about 18%, because the cuts are angled and handed.
The room shape. A plain rectangle adds nothing. A WC, a basin or an island adds 2–5%.
Small rooms. Under 12 m² adds 2%, under 6 m² adds 4%. One ruined cut is a much larger share of a small order, and there is no other room to use the offcut in.

That is why a 5 m² floor carries 16% on a straight grid while a 50 m² one carries 12% for the same layout — the small-room addition drops away, but the shape addition does not. The tables above include the small-room addition where it applies, which is why the per-square-metre figure is not constant down a column.

Tile size changes the count more than the waste

A 600 × 600 tile covers four times what a 300 × 300 does, so the count drops by roughly four. But the waste percentage barely moves, because waste is driven by cutting, not by tile size — and a large tile wastes more material per cut even though it wastes a similar percentage. On a small floor that matters: one spoiled 600 mm tile is most of a square metre.

What this table cannot tell you

It assumes a square room with nothing to cut around, a 3 mm joint, and tiles sold singly. Real rooms are none of those things. Boxes are the figure you actually order in, and a box of 600 × 600 usually holds four — so 64 tiles is 16 boxes, and 65 is 17. Put your own dimensions in the tile calculator and it will round to boxes for you.

Tile calculator — your room, your tile, rounded to boxes
Waste factor reference — where every percentage above comes from
Adhesive and grout — the other two things you have to order
A real bathroom, start to finish
The answer tables as JSON — with the inputs that produced each row

Last reviewed 2026-10-17. Figures generated from the tile calculator on this site. Your room will differ — run the numbers rather than reading across.

Sources and confidence

Every figure used on this page, what kind of figure it is, and where it came from. Figures marked as working estimates have no single authority behind them — they are the ones to check against your own supplier.

Provenance of the figures on this page.
Figure	Kind	Source	Note
Every tile count in the tables	Derived	Generated from this site's tile calculator	Produced by running the calculator across the grid, not typed in by hand. A test re-checks sample cells against the live tool.
Pattern waste percentages	Working estimate	no primary source consulted	Merchant estimating practice, rounded up. See the waste factor reference.
Tile pitch includes the joint	Derived	Geometry	A 600 mm tile with a 3 mm joint occupies 603 mm.

Derived Calculated from geometry. The formula is on this page. Published From a manufacturer data sheet or published standard, cited below. Working estimate Trade practice, rounded up. No single authority; the weakest category here.