Grout Calculator

Formula

The grout volume per unit area is calculated from the tile and joint dimensions:

Where:

• L = tile length
• W = tile width
• S = joint spacing (grout line width)
• D = joint depth (typically tile thickness)

This formula accounts for the grout lines running along both the length and width of each tile, shared between adjacent tiles.

Grout Type Guidelines

• Unsanded grout: Use for joints ≤ 1/8″ (3 mm). Best for wall tiles and polished stone
• Sanded grout: Use for joints > 1/8″ (3 mm). Better for floor tiles and wider joints
• Epoxy grout: Use for high-moisture areas, chemical resistance, and stain-proof joints

Coverage Reference

• A standard 25 lb (11.3 kg) bag of grout yields approximately 277 cu in (4.5 L) of mixed grout
• A 10 lb (4.5 kg) bag yields approximately 111 cu in (1.8 L) of mixed grout
• Actual coverage varies by manufacturer, grout type, and mixing consistency

Tips

• Always add 10% extra for waste, uneven joints, and filling low spots
• Mix only as much grout as you can use within 20–30 minutes
• Deeper joints require more grout — measure actual tile thickness, not nominal size
• For natural stone tiles, check if sanded grout could scratch the surface

You can embed this util on your own site as a widget. Adding ?embed=1 to the URL loads a compact version with just the tool itself; no header, menu, or documentation. Paste this snippet into your HTML:

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