Grout Calculator
Planning a tile project? Our free grout calculator tells you exactly how many bags of grout you need — for floors, walls, backsplashes, or showers. Enter your tile dimensions, joint width, and total square footage to instantly get your bag count, total weight (with 10% waste included), and a location-adjusted cost estimate. Works for sanded, unsanded, and epoxy grout.
Bags = Grout lbs × 1.10 (10% waste) ÷ Bag Size · Density: sanded 0.1875 · unsanded 0.165 · epoxy 0.22 lbs/in³
Always buy 10% more grout than calculated — color lots vary between production batches · Joint width has a bigger effect on quantity than tile size · Epoxy grout costs 3–5× more but never needs sealing
Estimates based on 2026 US average pricing. Coverage varies by tile porosity, joint depth, and grout brand. Always check the product data sheet for actual coverage rates.
How Does the Grout Calculator Work?
This grout calculator uses the industry-standard formula for estimating grout quantity — accounting for tile width, tile length, tile thickness, joint width, and total surface area. It then adds a 10% waste buffer and divides by your chosen bag size to give you an exact bag count. Not sure of your square footage? Use our square footage calculator to measure your room first.
The formula works by calculating the total volume of grout joints in cubic inches, converting that to pounds using the grout density, then dividing by bag size. Joint width has the biggest impact on quantity — a 1/4" joint uses roughly twice as much grout as a 1/8" joint on the same tile. This calculator accounts for three grout types (sanded, unsanded, epoxy) each with their own density value, so your estimate is accurate regardless of product type.
Grout is sold in fixed bag sizes — 5, 10, 25, and 50 lb. Buying the wrong size wastes money. A 50 lb bag for a small bathroom floor leaves you with leftover product that hardens in storage within months. This calculator outputs the exact number of bags in your chosen size so you buy precisely what you need with just a 10% safety margin built in.
Sanded vs. Unsanded vs. Epoxy Grout
Choosing the right grout type is as important as choosing the right tile. Use the wrong type and it will either crack (unsanded in wide joints) or permanently scratch your tile surface (sanded on polished stone). If you're tiling a bathroom floor or shower, you'll also want to cross-reference our bathroom remodel cost calculator to keep your full project budget on track.
| Grout Type | Joint Width | Coverage / 10 lb | Cost / 10 lb | Best For |
|---|---|---|---|---|
| Sanded | ≥ 1/8" | 50–100 sq ft | $12 – $20 | Floor tile, most walls, stone with wide joints |
| Unsanded | < 1/8" | 60–120 sq ft | $14 – $22 | Wall tile, glass mosaic, polished marble |
| Epoxy | 1/16" – 1/2" | 40–80 sq ft | $45 – $80 | Kitchens, showers, commercial — no sealing needed |
Sanded grout contains fine silica particles that will permanently scratch polished marble, travertine, glass tile, and glazed ceramic. For any tile with a high-gloss or polished surface — even if the joint is 1/8" wide — use unsanded or non-sanded grout. When in doubt, test a small hidden area before grouting the full surface.
For kitchen tile projects specifically, epoxy grout is often worth the extra cost because kitchen surfaces face constant exposure to oil, food acids, and cleaning chemicals. You can estimate your full kitchen tile and materials budget using our kitchen remodel cost calculator.
Grout Coverage by Tile Size
Coverage varies significantly based on tile size and joint width. Smaller tiles have more joints per square foot, which means dramatically more grout. Here are approximate ranges for a 10 lb bag of sanded grout at common joint widths. To find your tile quantity first, see our tile calculator.
| Tile Size | Joint Width | Coverage (10 lb bag) | Bags per 100 sq ft |
|---|---|---|---|
| 2×2" Mosaic | 1/8" | 15 – 25 sq ft | 4 – 7 bags |
| 4×4" Wall Tile | 3/16" | 30 – 45 sq ft | 2 – 4 bags |
| 6×6" Tile | 3/16" | 45 – 60 sq ft | 2 – 3 bags |
| 12×12" Tile | 3/16" | 60 – 80 sq ft | 1 – 2 bags |
| 18×18" Tile | 1/4" | 75 – 100 sq ft | 1 – 2 bags |
| 24×24" Large Format | 1/4" | 90 – 120 sq ft | 1 bag |
Going from a 1/8" joint to a 1/4" joint on the same tile roughly doubles the amount of grout needed. This is the single biggest variable in grout estimation — more than tile size. If you're deciding between joint widths, factor the extra grout cost into your total flooring budget. Use our flooring cost calculator to see the full picture including labor and underlayment.
Grout Cost (2026)
Grout is one of the lowest-cost materials in any tile project — but choosing the wrong type or bag size can inflate costs unnecessarily. Prices below reflect US national averages from major retailers including Home Depot and Lowe's.
| Product | Bag Size | Cost per Bag | Cost per Sq Ft |
|---|---|---|---|
| Budget Sanded Grout | 10 lb | $10 – $15 | $0.13 – $0.25 |
| Mid-Range Sanded Grout | 10 lb | $15 – $22 | $0.20 – $0.40 |
| Premium Sanded Grout | 10 lb | $22 – $35 | $0.30 – $0.60 |
| Unsanded Grout | 10 lb | $14 – $24 | $0.15 – $0.40 |
| Epoxy Grout | 9 lb (kit) | $45 – $80 | $0.60 – $2.00 |
| Professional Labor | — | — | $3.00 – $7.00 / sq ft |
If you're hiring out the tile work, grout is typically included in the installer's labor quote. To understand what a full professional tile installation costs in your area, see our flooring cost calculator which breaks down both material and labor by sq ft.
Example Calculation
Grouting a 100 sq ft bathroom floor with 12×12" tile, 3/8" thick, 3/16" joints, sanded grout, 10 lb bags. (Use our area calculator if you need help finding your room's square footage first.)
(12 + 12) ÷ (12 × 12) = 24 ÷ 144 = 0.1667
Step 2 — Apply joint width and tile depth:0.1667 × 0.1875 (joint) × 0.375 (depth) = 0.01172
Step 3 — Convert area to sq in and apply density:0.01172 × 0.1875 (sanded density) × (100 × 144) = 31.7 lbs
Step 4 — Add 10% waste buffer:31.7 × 1.10 = 34.9 lbs
Step 5 — Convert to bags (10 lb bags):34.9 ÷ 10 = 3.49 → buy 4 bags
Step 6 — Material cost (mid-range at $18/bag):4 × $18 = ~$72 in grout
Mixing & Application Tips
Mixing Grout
- Mix only what you can use in 20–30 minutes — grout begins to set quickly, especially in warm conditions. Start with half a bag until you know your working pace.
- Add water to grout, not grout to water — pour the measured water into the bucket first, then slowly add the grout powder. This prevents dry clumps at the bottom that won't fully incorporate.
- Let it slake for 10 minutes — after initial mixing, let the grout rest for 10 minutes then remix briefly. This activates all the cement particles and results in a smoother, more workable consistency with better adhesion.
- Consistency should be like peanut butter — not too soupy (causes sag in wall joints) and not too stiff (tears joints during application). Adjust with very small amounts of water, a tablespoon at a time.
Application Tips
- Hold the float at 45° — use a rubber grout float pressed firmly at a 45° angle to pack grout deep into joints. Work diagonally across the joint lines to avoid dragging grout back out as you move.
- Clean the float often — scrape excess grout off the float every few passes so you're never spreading already-stiffening material back over fresh joints.
- Wait 15–30 minutes before wiping — let the grout firm up slightly before cleaning. Use a damp (not wet) sponge in wide circular motions, wringing it nearly dry each time. Excess water weakens the joint.
- Seal within 72 hours — apply a penetrating grout sealer after the grout fully cures. Skipping this on a bathroom floor or kitchen backsplash causes staining within weeks. Reapply every 1–3 years depending on traffic.
For sanded grout: Mapei Keracolor S and Custom Building Products PolyBlend Plus consistently rank highest for color consistency, workability, and ease of cleaning. For unsanded: Laticrete PermaColor Select. For epoxy: PROMA Starlike EVO or TEC AccuColor EFX. All are available at Home Depot and Lowe's in 50+ colors. Check the Tile Council of North America for installation standards on your specific tile type.