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Grout Calculator

Calculate the exact pounds of grout needed for any tile project. Enter your tile dimensions, joint width, tile thickness, and total square footage. The calculator handles all common tile sizes — from 1-inch mosaics to 24×48 large-format tiles — and accounts for both sanded and unsanded grout. Includes a coverage chart for quick reference.

Tile & Grout Specifications

Narrower than 1/8″ uses unsanded grout. 1/8″ and wider uses sanded grout.
Total floor or wall area to be grouted.
Sanded: $1–$2/lb. Unsanded: $1.50–$3/lb. Epoxy: $5–$12/lb.

🧹 Grout Estimate

Tile Size—
Joint Width—
Tile Thickness—
Total Area—
Grout Needed —
Grout Type—
Grout Bags (10 lb each)—
Total Grout Cost—
Coverage per 10 lb Bag (approx.)—
Formula: grout (lbs) = (L+W) ÷ (L×W) × joint × thickness × area × 0.002. Always buy 10–15% extra to account for variations in joint width and waste.

Grout Coverage Chart

Quick reference for approximate grout coverage across common tile sizes and joint widths. Values assume 3/8″ tile thickness and 100 sq ft of area. Your actual coverage may vary — use the calculator above for precise results.

Tile Size 1/16″ Joint 1/8″ Joint 3/16″ Joint 1/4″ Joint 3/8″ Joint
1″ × 1″ Mosaic3.0 lbs6.0 lbs9.0 lbs12.0 lbs18.0 lbs
2″ × 2″1.5 lbs3.0 lbs4.5 lbs6.0 lbs9.0 lbs
3″ × 6″ Subway1.1 lbs2.3 lbs3.4 lbs4.5 lbs6.8 lbs
4″ × 4″0.8 lbs1.5 lbs2.3 lbs3.0 lbs4.5 lbs
6″ × 6″0.5 lbs1.0 lbs1.5 lbs2.0 lbs3.0 lbs
6″ × 24″ Plank0.4 lbs0.8 lbs1.3 lbs1.7 lbs2.5 lbs
8″ × 8″0.4 lbs0.8 lbs1.1 lbs1.5 lbs2.3 lbs
12″ × 12″0.3 lbs0.5 lbs0.8 lbs1.0 lbs1.5 lbs
12″ × 24″0.2 lbs0.4 lbs0.6 lbs0.8 lbs1.1 lbs
18″ × 18″0.2 lbs0.3 lbs0.5 lbs0.7 lbs1.0 lbs
24″ × 24″0.1 lbs0.3 lbs0.4 lbs0.5 lbs0.8 lbs
24″ × 48″0.1 lbs0.2 lbs0.3 lbs0.4 lbs0.6 lbs
Coverage values are per 100 sq ft with 3/8″ tile thickness. Double for 200 sq ft, halve for 50 sq ft. Thicker tiles and wider joints increase grout volume proportionally.

How to Use the Grout Calculator

Select a common tile size from the dropdown, or choose \"Custom Size\" and enter your exact tile dimensions in inches. Select your grout joint width — 1/8″ is the most common for floor and wall tile, 1/16″ is for rectified (precision-cut) tiles, and 1/4″+ works best for irregular stone or rustic tiles. Choose your tile thickness based on your specific tile — the default 3/8″ covers most standard ceramic and porcelain floor tiles.

Enter the total square footage of the area you're grouting. For floors, multiply length × width. For walls, measure each wall section and add them up. The calculator uses the industry-standard grout formula: grout (lbs) = (tile_width + tile_length) ÷ (tile_width × tile_length) × joint_width × tile_thickness × area_sqft × 0.002. This accounts for all the grout lines in both directions of your tile layout.

The results tell you the total pounds of grout needed, the grout type (sanded for joints 1/8″ and wider; unsanded for narrower joints), the number of 10 lb bags to purchase, the total cost, and the approximate coverage per bag for your specific tile configuration. Always buy at least one extra bag — running out mid-project means a visible color seam.

Grout Application Tips

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Frequently Asked Questions

The amount varies significantly by tile size and joint width. For 12×12 inch tiles with 1/8″ joints and 3/8″ thickness, you need about 0.005 lbs per sq ft — or about 0.5 lbs per 100 sq ft. For 1-inch mosaic tile with 1/8″ joints, you need about 6 lbs per 100 sq ft — 12× more. The formula is: grout (lbs/sqft) = (L+W)÷(L×W) × joint × thickness × 0.002. Use our calculator above — it handles the math for any tile size and joint configuration.
Use sanded grout for joints 1/8″ and wider — the sand provides strength and prevents shrinkage cracking in wider joints. Use unsanded grout for joints narrower than 1/8″ and for soft, polished, or scratch-prone tiles like marble, glass, or polished porcelain. Unsanded grout flows into tight joints without scratching the tile surface. Epoxy grout is a third option: stain-proof and waterproof, ideal for showers and countertops, but harder to install and 3–5× the cost of cement-based grout.
Recommended grout joint widths: 1/16″ for rectified (precision-cut) tiles with perfectly uniform edges; 1/8″ for most standard ceramic and porcelain tiles (the most common width); 3/16″ for slightly irregular tiles or those with moderate edge variation; 1/4″ for handmade tiles, tumbled stone, or slate with natural edge variation; 3/8″–1/2″ for very irregular stone, quarry tile, or rustic terracotta. For mosaic sheets (1×1 or 2×2 tiles), the joint is typically pre-set in the sheet material at 1/8″–3/16″.
The formula is the same for walls and floors — both use the same tile size, joint width, and thickness inputs. The only difference is the total square footage. For walls, measure each wall section (height × width) and add them together. Don't subtract small fixtures like shower arms or soap dishes — it's easier to have a little extra grout. For shower floors (pans), use the floor area plus the curb and any benches. Always use epoxy grout for shower floors and use sanded or epoxy for shower walls (un-sanded can wash out in wet conditions over time).
Standard cement-based grout needs 72 hours (3 days) to fully cure before applying sealer. Latex-modified grout (pre-mixed or with additive) can be sealed after 24–48 hours. Epoxy grout does not need sealing — it's inherently stain-proof. The best way to test: place a few drops of water on the grout. If it beads up, it's still too green. If it absorbs within 60 seconds, it's ready for sealer. Never seal grout that feels damp — trapped moisture causes efflorescence (white powdery deposits). Re-seal cement-based grout every 1–2 years in kitchens and bathrooms, every 2–3 years in lower-moisture areas.