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Thinset Coverage Chart: Sq Ft per Bag by Trowel Size

How much does a bag of thinset cover? Every mortar on this site, in one table, at the three trowel notches that are interchangeable between brands. All figures are square feet per bag as printed on the manufacturer's data sheet.

Want bags for your own area, not square feet per bag? The thinset mortar calculator does the arithmetic for every product at once.

Sq ft covered by one bag, by trowel notch

Sq ft covered by one bag, by trowel notch. Square feet per bag (1 m² = 10.7639 sq ft). Only notches that exist on more than one brand are shown; U-notch and sheet-membrane notches are product-specific and stay on the product pages.
ProductBag1/4" x 1/4"1/4" x 3/8"1/2" x 1/2"
ARDEX X 77 MICROTEC
ARDEX		40 lb (18 kg)11082.555
Custom ProLite Premium
Custom		30 lb (13.6 kg)90–10063–7045–50
Custom VersaBond Professional
Custom		50 lb (22.68 kg)85–9560–67– not rated at this setting
Custom VersaBond-LHT
Custom		50 lb (22.68 kg)90–10060–6742–47
LATICRETE 253 Gold
LATICRETE		50 lb (22.7 kg)80–9560–70– not rated at this setting
LATICRETE 254 Platinum
LATICRETE		50 lb (22.7 kg)80–9560–7035–40
LATICRETE 254 Platinum Plus
LATICRETE		25 lb (11.3 kg)80–9560–7035–40
Mapei Keraflex Plus
MAPEI		44 lb (20 kg)75–9055–6538–45
Mapei Ultraflex 2
MAPEI		50 lb (22.7 kg)75–9055–65– not rated at this setting
Mapei Ultraflex 2 LT
MAPEI		50 lb (22.7 kg)75–9055–6538–45

A range is the manufacturer's own range for that notch: the low end assumes little mortar stays in the ridges, the high end a full, well-combed bed. The calculator divides by the low end so you do not run short.

How to read a thinset coverage chart

Two numbers decide how far a bag of thinset goes: the size of the trowel notch and how much of the mortar actually stays in the ridges once the tile is pressed down. Manufacturers publish one row per notch because the notch is the only part a buyer controls. A 1/4 x 1/4 in square notch leaves a bed about 1/8 in deep after the tile is embedded; a 1/4 x 3/8 in notch leaves roughly 3/16 in; a 1/2 x 1/2 in notch leaves about 1/4 in. Twice the bed depth means roughly half the square footage per bag, which is why the columns in the table fall away so quickly.

Which notch for which tile

As general practice, mosaics and tiles up to about 4 in take a 1/4 x 1/4 in square notch. Tiles from roughly 6 x 6 in up to 16 x 16 in on a flat substrate take 1/4 x 3/8 in. Anything larger, any tile with a deep back pattern, and any floor that is not flat takes 1/2 x 1/2 in or bigger, and the tile should be back-buttered as well. When you back-butter, the bag covers less than the chart says, because mortar also goes on the back of every tile. Raise the waste figure in the calculator to 15% or 20% in that case.

Worked example: 200 sq ft at 1/4 x 3/8 in

200 sq ft plus 10% waste is 220 sq ft of bed to fill. At 1/4 x 3/8 in, Custom VersaBond-LHT covers 60 to 67 sq ft per 50 lb bag, so 220 ÷ 60 = 3.67, which rounds up to 4 bags (200 lb). ARDEX X 77 covers a flat 82.5 sq ft per 40 lb bag, so the same job needs 220 ÷ 82.5 = 2.67, or 3 bags (120 lb). Same floor, same notch, one bag and 80 lb of powder apart. Step up to a 1/2 x 1/2 in notch and the VersaBond-LHT figure falls to 42 to 47 sq ft per bag, so the job becomes 6 bags (300 lb); LATICRETE 254 Platinum, at 35 to 40 sq ft per bag, needs 7 bags (350 lb).

Bag size matters as much as coverage

Bags in this table run from 25 lb to 55 lb. A 25 lb bag that covers 60 sq ft and a 50 lb bag that covers 60 sq ft are not the same value, and the lighter bag is much easier to carry up a stair. Compare the coverage column first, then the bag weight, then the shelf price — that is the only order that gives a real per-square-foot cost.

For your own area and notch, use the thinset coverage calculator, which runs this same table against every product at once and tells you how many bags to buy. Each product name above links to its own page, where the full data sheet coverage table, mixing water and open time are listed.

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