Tile Grout Calculator
Estimate grout needed for tiled surfaces.
Last updated 2026-08-21
What Is a Tile Grout Calculator?
A tile grout calculator estimates the amount of grout you need based on tile size, tile thickness, and grout joint width. Grout volume grows quickly with wider joints and thicker tiles, so a good estimate keeps you from running short. It is for homeowners finishing a tile installation who want to buy the right number of grout bags.
How It Works
Grout (ft³) = (2 × (Tile W + Tile L) × Tile count × Joint × Thickness) ÷ 1728.
Example
100 sq ft of 12×12 tile, 1/4 in joint, 3/8 in thick: ≈ 0.26 cu ft ≈ 36 lb of grout.
How to Calculate
- Enter the project area in square feet, such as 100 square feet.
- Enter your tile dimensions in inches, like a 12 by 12 inch tile.
- Enter the tile thickness, commonly 3/8 inch for floor tile.
- Enter the grout joint width, such as 1/4 inch for floor tile or 1/8 inch for wall tile.
- Read the result in cubic feet and pounds. For 100 square feet of 12x12 tile with a 1/4 inch joint, expect about 0.26 cubic feet, or roughly 36 pounds, before adding 10 percent for mixing and touch ups.
Approximate Grout Coverage by Joint and Tile Size
| Tile Size | Joint Width | Sq Ft per 25 lb Bag |
|---|---|---|
| 4x4 in | 1/8 in | 175 |
| 6x6 in | 1/8 in | 160 |
| 12x12 in | 1/8 in | 190 |
| 12x12 in | 1/4 in | 95 |
| 12x24 in | 1/4 in | 80 |
| 24x24 in | 3/8 in | 45 |
Sources
Frequently Asked Questions
How much grout does a bag make?
A standard 25 lb bag of grout covers roughly 100–200 sq ft depending on joint and tile size.
Wider joints need more grout?
Yes — joint width and tile thickness are the biggest drivers of grout volume.
Should I order extra grout?
Yes, add 10% for mixing and touch-ups. Grout color can vary between batches.
Estimate the cost with the Flooring Cost Calculator or browse Flooring Calculators