Tile grout and thinset calculator
Enter the area, the tile and the grout joint, and pick the trowel. This works out the grout by the volume of the joints and the thinset by the coverage a bag gives with that trowel.
= 0.125"
= 0.375"
Advanced settings85 sq ft a bag · 25 lb grout bags · 106 lb/ft³ · 10% waste
Per 50 lb bag, from the bag's chart
Cement grout; epoxy is lighter
To buy
Grout, 25 lb bags
1
Thinset, 50 lb bags
2
How it adds up
- Share of the floor that is joint
- 2.1%
- Grout volume
- 133 in³
- Grout, with waste
- 9.0 lb
- Thinset
- 85 sq ft to a bag
Where to buy this
- 1 × 25 lb groutHome DepotLowe's
- 2 × 50 lb thinsetHome DepotLowe's
Sanded grout is for joints of 1/8" and wider; narrower joints take unsanded. The search is for the material, not the colour.
Plain search links, nothing sponsored. Prices and stock are the shop's, and a local lumberyard will usually beat both on solid stock.
Worked example: 120 sq ft of 12" tile
12" × 12" tile with 1/8" joints is 2.1% joint, so 120 sq ft at 3/8" deep takes 133 in³ of grout — 9.0 lb with 10% waste, or 1 bag of 25 lb.
At 85 sq ft to a 50 lb bag of thinset, the floor takes 2 bags.
- Grout
- 1 × 25 lb (9.0 lb)
- Thinset
- 2 × 50 lb
- Joint share of the floor
- 2.1%
These are the figures the calculator above opens on. Change any field and it works the same problem for your numbers.
About grout and thinset
- How much grout do I need for 100 square feet?
- About 7 lb in 12" tile with an 1/8" joint 3/8" deep, and about 13 lb in 6" tile with the same joint — smaller tile is more joint for the same floor. A wider joint or a thicker tile raises it in proportion, which is why the calculator asks for both.
- How many square feet does a bag of thinset cover?
- It depends on the trowel. A 50 lb bag covers about 85–95 sq ft with a 1/4" × 1/4" square notch and about 60–67 sq ft with a 1/4" × 3/8", by Custom Building Products' charts. Larger tiles want the bigger notch, and the bag's own chart is the figure to trust.
- Sanded or unsanded grout?
- Sanded for joints 1/8" and wider, where the sand stops the grout shrinking and cracking in the joint; unsanded for narrower joints it would not pack into. Both are sold by weight and estimated the same way here — only the bag changes.
You might also need
- Tile calculatorFull tiles across the middle and a sized cut tile at every edge, centred or started from one wall.
- Flooring calculatorHow many rows, how wide to rip the first one, and where the end joints fall so they never line up.
- Caulk and sealantTubes of caulk for a run of joints, from the bead size, with the feet one tube actually lays.