How much grout for a tile floor?
Quick Answer
A 100 sq ft tile floor with 12×12-inch tiles and 3/16-inch joints needs about 1 bag (25 lbs) of sanded grout. Smaller tiles or wider joints require more grout — a floor with 4×4 tiles may need 3 bags. Use the tile manufacturer's grout coverage chart for exact quantities.
Quick Reference Table
| Tile size × joint width | Grout bags for 100 sq ft |
|---|---|
| 4×4" tile, 1/8" joint | 3 bags (25 lbs each) |
| 12×12" tile, 3/16" joint | 1 bag |
| 12×12" tile, 1/4" joint | 1.5 bags |
| 18×18" tile, 3/16" joint | 0.75 bags |
| 24×24" tile, 1/8" joint | 0.5 bags |
How to Calculate It Yourself
- 1
Find the grout coverage on your grout bag label — it lists sq ft per bag by tile size and joint width.
- 2
If unavailable, use the formula: lbs per sq ft = (tile perimeter × joint depth × joint width) ÷ (tile area × 144) × grout density.
- 3
Simpler rule: add 10% to calculated amount for waste and touch-ups.
- 4
Mix in small batches — grout has a 30-minute working time.
Pro Tip
Buy grout from the same dye lot for consistency. Grout color shifts slightly between lots — even matching bags from different batches can show variation after installation.
Assumptions to Check
Before ordering materials, confirm the dimensions, product coverage, waste factor, and local installation requirements for your project. Manufacturer coverage tables and local code rules can change the final quantity, especially for structural work, exterior projects, and irregular layouts.
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