# Tile Calculator

Area and tile size to pieces, boxes and thinset.

- Page: https://jianzhujisuan.com/en/tile-quantity
- Category: Finishes (https://jianzhujisuan.com/en/c/finishes)
- Chinese version: https://jianzhujisuan.com/zh/tile-quantity.md
- Data checked: 2026-10-25

## Quick result

With the default inputs (Area to tile 100 ft², Tile width 12 in, Tile height 24 in, Pieces per box 8 pcs, Waste 10%): **Tile pieces 55 pcs**

## Inputs

| Parameter | Type | Default | Unit | Note |
|---|---|---|---|---|
| Area to tile | number | 100 | ft² |  |
| Tile width | number | 12 | in |  |
| Tile height | number | 24 | in |  |
| Pieces per box | number | 8 | pcs |  |
| Waste | number | 10 | % |  |

## Formula

- **Tile area = W × H ÷ 144**: inches to square feet
- **Pieces = area ÷ tile area × (1+waste)**: round up
- **Boxes = pieces ÷ per box**: round up
- **Thinset = area ÷ 100 bags**: 3/8 in notch, 50 lb bags

## Worked example

100 ft² in 12x24 tiles, 8 per box, 10% waste: each tile is 2 ft², so 50 net, 55 with waste and 7 boxes (56 pieces); one bag of thinset and about 35 lb of grout.

## Questions

### How much waste?

10% for a straight lay, 12% for running bond and 15-20% for diagonal or herringbone, which leaves triangles at every edge. Small bathrooms and rooms full of pipe penetrations need more. Large format wastes less in proportion but each mistake costs more - one bad cut on a 12x24 is 2 ft² gone. Buy the extra box; a later top-up from another lot will show.

### How much thinset?

About one 50 lb bag per 100 ft² with a 3/8 in notch trowel. Notch size follows tile size: 1/4 in under 8 in tiles, 3/8 in for 8-15 in, and 1/2 in above 15 in. Bigger notches use more, taking large format to roughly 1.5 bags per 100 ft². An uneven floor needs levelling compound on top of that, priced separately.

### Does it need waterproofing?

Wet areas - showers and around baths - must be waterproofed, and that means a membrane under the tile, not a surface coating. Install a sheet or liquid membrane over the substrate below the thinset, turned up at least 4 in at the perimeter and to 72 in or shower head height in a shower. Floors need a 24 hour flood test. Skip it and a leak into the room below means tearing the whole floor out.

## Related tools

- [Paint Coverage Calculator](https://jianzhujisuan.com/en/paint-coverage): Enter room size, ceiling height, openings and number of coats to get total area, litres needed and how many cans to buy.
- [Tile Calculator](https://jianzhujisuan.com/en/tile-count): Enter the area to cover, pick a tile size and waste factor to get tiles and boxes required.
- [Flooring Quantity Calculator](https://jianzhujisuan.com/en/flooring): Planks and packs from room size and board format, with waste by laying pattern.
- [Wallpaper Roll Calculator](https://jianzhujisuan.com/en/wallpaper): Drops and rolls from perimeter, height and pattern repeat.
- [Ceiling Grid Calculator](https://jianzhujisuan.com/en/ceiling-grid): Main and cross runner lengths, hangers and fittings from ceiling size.
- [Plasterboard Quantity Calculator](https://jianzhujisuan.com/en/gypsum-board): Sheets, screws and joint tape from area, sheet size and layers.

---

Generated by BuildCalc. All calculations run in your browser; no data is uploaded. Formulas follow national standards and common trade practice; local codes govern.