Grout Calculator
A 10 by 10 foot floor of 12 by 12 inch tile, with a 1/8 inch joint and a 3/8 inch depth, is 6.51 lb of grout, 1 bag at 25 lb.
Last updated . Floor size starts in feet. Tile, joint, and depth start in inches. Switch any of them to meters, yards, millimeters, or centimeters. Density starts at 100 lb/ft³. The bag starts at 25 lb. Both are planning figures. No price.
Enter the floor, the tile, the joint width, and the joint depth. The result is the grout in the joints, in cubic feet, pounds, and bags.
Tile count: tile calculator. Mortar under the tile: thinset calculator. Sand-and-cement screed: screed calculator. How many extra tiles the layout needs is the tile waste guide.
Grout in the joints
Depth starts at 0.375 in, a 3/8 in planning thickness for a floor tile. The joint is filled about to that thickness. It is not a brand’s tile.
100 lb/ft³ is a planning density. The 25 lb bag is a planning bag, not a brand yield. No price.
Results
How the grout is counted
The standard formula is volume = area × joint width × joint depth × (tile length + tile width) ÷ (tile length × tile width). Length and width are the tile face. The corner square, where the two joints meet, is included on both edges. That is a little more grout than a module that counts the corner once. Pounds = cubic feet × density. Density starts at 100 lb/ft³, a planning figure, not a brand.
On the opening floor the volume is 0.07 ft³. That is about 0.002 m³, so the cubic-meter line prints 0.00 at two decimals. Lead with the cubic feet and the pounds: 6.51 lb, which is 1 bag of the 25 lb planning bag. Depth starts at 0.375 in, a 3/8 in planning thickness, with the joint filled about to that thickness.
Worked example
Leave every field as it opens: floor 10 ft by 10 ft, tile 12 in by 12 in, joint 0.125 in, depth 0.375 in, density 100 lb/ft³, bag 25 lb. Area reads 100.00 ft² · 9.29 m². Volume reads 0.07 ft³ · 0.00 m³. Weight reads 6.51 lb. Bags read 1.
Smaller tile and a wider joint both add joint length. The bag moves once the floor or the tile is small enough for the pounds to pass 25.
| Tile | Floor | Joint | Depth | Volume | Weight | Bags |
|---|---|---|---|---|---|---|
| 12 × 12 in | 10 × 10 ft | 0.125 in | 0.375 in | 0.07 ft³ · 0.00 m³ | 6.51 lb | 1 |
| 6 × 6 in | 10 × 10 ft | 0.125 in | 0.375 in | 0.13 ft³ · 0.00 m³ | 13.02 lb | 1 |
| 6 × 6 in | 10 × 20 ft | 0.125 in | 0.375 in | 0.26 ft³ · 0.01 m³ | 26.04 lb | 2 |
| 4 × 4 in | 10 × 10 ft | 0.125 in | 0.375 in | 0.20 ft³ · 0.01 m³ | 19.53 lb | 1 |
| 4 × 4 in | 10 × 20 ft | 0.125 in | 0.375 in | 0.39 ft³ · 0.01 m³ | 39.06 lb | 2 |
| 12 × 12 in | 10 × 10 ft | 0.25 in | 0.375 in | 0.13 ft³ · 0.00 m³ | 13.02 lb | 1 |
| 12 × 12 in | 10 × 10 ft | 0.125 in | 0.5 in | 0.09 ft³ · 0.00 m³ | 8.68 lb | 1 |
Frequently asked questions
How much grout for 12 by 12 tile on 100 square feet?
Leave the floor at 10 ft by 10 ft, the tile at 12 in by 12 in, the joint at 0.125 in, and the depth at 0.375 in. Area reads 100.00 ft² · 9.29 m². Volume reads 0.07 ft³ · 0.00 m³. Weight reads 6.51 lb. Bags read 1 at the 25 lb planning bag. 0.07 cubic feet is about 0.002 cubic meters, so the meter line prints 0.00.
What formula and density does this use?
Volume = area × joint width × joint depth × (tile length + tile width) ÷ (tile length × tile width). The corner square is included on both edges, so this is a little more grout than a module that counts the corner once. Pounds are cubic feet times 100 lb/ft³. That density is a planning figure, not a brand. The bag starts at 25 lb.
How much grout for 6 by 6 tile?
Set the tile to 6 in by 6 in and the floor to 10 ft by 20 ft, and leave the joint and the depth. Area reads 200.00 ft² · 18.58 m². Volume reads 0.26 ft³ · 0.01 m³. Weight reads 26.04 lb. Bags read 2. The same 6 in tile on the 10 by 10 floor is 0.13 ft³ · 0.00 m³, 13.02 lb, and 1 bag.
How much grout for 4 by 4 tile?
Set the tile to 4 in by 4 in on the 10 by 10 floor. Volume reads 0.20 ft³ · 0.01 m³. Weight reads 19.53 lb. Bags read 1. On a 10 by 20 floor that doubles: 0.39 ft³ · 0.01 m³, 39.06 lb, and 2 bags. Smaller tile means more joint length in the same floor.
What if the joint is 1/4 inch?
Set the joint width to 0.25 in and leave the 12 in tile, the 0.375 in depth, and the 10 by 10 floor. Volume reads 0.13 ft³ · 0.00 m³. Weight reads 13.02 lb. Bags stay 1. The volume is linear in the joint width, so 1/4 in is double the 1/8 in result of 6.51 lb.
What does a deeper joint change?
Set the joint depth to 0.5 in and leave the rest of the default. Volume reads 0.09 ft³ · 0.00 m³. Weight reads 8.68 lb. Bags stay 1. Depth starts at 0.375 in, a 3/8 in planning thickness for a floor tile, filled about to that thickness. It is not a brand’s tile.
Is this thinset or screed?
No. This page is the grout in the joints, in pounds and bags. The mortar under the tile is the thinset calculator. A sand-and-cement floor screed, with cement bags and sand volume, is the screed calculator. The tile count is the tile calculator.