Mosaic Tile Calculator

How many mosaic sheets do I need?

A sheet is laid with a grout joint all around it, so it covers its own size plus one joint each way. A 12 × 12 in nominal sheet that really measures 11 3/4 in covers about 0.97 sq ft with 1/16 in joints. Divide the floor area plus waste by that coverage and round up; with the sheets per box entered, you get whole boxes. If the box states its coverage, enter that instead.

Waste is lower than for large tile because sheets are cut along the joints: 10% by default. Loose hexagon tile, where every cut at the wall is angled, defaults to 15%.

Hexagon tile: measuring flat to flat

Hexagons are sized across the flats, from one side to the opposite side. If yours is labeled by the distance between opposite points, tick “measured point to point” and the size is multiplied by √3/2 (0.866). A 2 in hexagon measured flat to flat is about 2 5/16 in point to point.

The mosaic formulas

sheets = ⌈A × (1 + waste) ÷ ((a + j)(b + j))⌉; G_hex = 2 × j × d × ρ ÷ s; G_penny = f × d × ρ

a × b is the sheet size, j the joint, s the hexagon size flat to flat, d the joint depth (the tile thickness), ρ the grout density and f the share of the surface between the pennies: f = 1 − (π × D² ÷ 4) ÷ c, with c = √3/2 × (D + j)² for staggered pennies or (D + j)² on a square grid.

Worked example

Area 30 sq ft, 11 3/4 in sheets with 1/16 in joints: each sheet covers 11 13/16 × 11 13/16 in = 0.969 sq ft.
Sheets: 30 × 1.10 ÷ 0.969 = 34.1 → 35 sheets → 4 boxes of 10.
3/4 in penny rounds, 1/8 in spacing, 1/4 in deep, staggered: f = 0.334, G = 0.70 lb per sq ft.
Grout: 30 × 0.70 × 1.15 = 24.0 lb → one 25 lb bag.

How much grout for penny round and hexagon tile

Small pieces mean much more joint per square foot. For square and rectangular tile the grout rate is (L + W) ÷ (L × W) × joint width × depth × density, as in the grout calculator. Hexagons have twice the joint length of a square of the same size. Penny rounds are different again: the gaps between circles are wide, so grout fills a fixed share of the surface — about a third with staggered pennies.

3/4 in pennies with 1/8 in spacing take about 0.70 lb of grout per sq ft at 1/4 in deep (0.88 lb on a square grid). 1 in hexagons with 1/16 in joints take about 0.26 lb. 12 × 12 in tile with 1/8 in joints takes 0.065 lb — about ten times less than the pennies.

Thinset and trowel for mosaics

The trowel follows the size of one piece, not the sheet. Pieces under 4 in take a 3/16 in V-notch at about 0.31 lb per sq ft; large loose hexagons step up to the notch their size calls for, as in the thinset calculator. White thinset is common under glass and light-colored mosaics.

Frequently asked questions

How many mosaic sheets per square foot?

About one: a 12 × 12 in nominal sheet covers 0.97 sq ft with 1/16 in joints, so 100 sq ft takes 104 sheets before waste and about 114 with 10%.

How much grout for penny tile?

Roughly 0.6 to 0.9 lb per sq ft at 1/4 in deep — about ten times as much as 12 × 12 tile. It depends on the spacing and on whether the pennies are staggered or on a square grid.

How do you measure hexagon tile?

Across the flats, from one side to the opposite side. If the size on the box is point to point, the calculator converts it with √3/2.

Do mosaics need a different thinset?

Not a different product, but a smaller notch — usually a 3/16 in V-notch for pieces under 4 in — and often white thinset under glass or light colors.

Does it work for large hexagon tile?

Yes. Choose a loose 8 in or 10 in hexagon, or enter any size: pieces are counted as √3/2 × (s + j)² each, with 15% waste for the angled cuts.

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Last updated October 19, 2026

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