How much grout does subway tile need?
Classic 3×6" subway tile is small, so it has a lot of grout joint per square foot compared to floor tile. The table below shows estimates for common subway sizes. The calculator above is preset for a 3×6" ceramic subway tile about 5/16" thick with 1/16" joints, a common backsplash setup.
| Tile | Thickness | Joint | Sanded | Unsanded |
|---|---|---|---|---|
| 2×8" | 5/16" | 1/16" | 10.7 lbs | 8.7 lbs |
| 3×6" | 5/16" | 1/16" | 8.5 lbs | 7.0 lbs |
| 3×6" | 5/16" | 1/8" | 17.0 lbs | 14.0 lbs |
| 3×12" | 5/16" | 1/16" | 7.1 lbs | 5.8 lbs |
| 4×12" | 3/8" | 1/8" | 13.6 lbs | 11.2 lbs |
| 4×16" | 3/8" | 1/8" | 12.8 lbs | 10.5 lbs |
A typical kitchen backsplash is 25 to 40 square feet, so even with 3×6 tile you usually need well under 10 lbs of grout. A 10 lb bag is often plenty. Check the result above against your actual area.
Joint width for subway tile
Subway tile is commonly set with joints between 1/16" and 1/8". Thin joints give the classic tight look and call for unsanded grout. Handmade or uneven-edged subway tile needs wider joints to hide size differences between tiles.
Joint width has a big effect: going from 1/16" to 1/8" doubles the grout you need. Pick your spacer size before buying grout.
Measuring a backsplash
- Measure the width and height of each wall section in inches.
- Multiply width by height for each section and add them together.
- Subtract large openings like windows. Don't bother subtracting outlets.
- Divide the total by 144 to convert square inches to square feet.
For more on the formula behind these numbers, see how much grout do I need.