Grout Calculator — Kg per area
Calculate the exact kg of grout needed for any tiled floor or wall. Based on tile size, gap width and thickness. Includes coverage chart and bag count.
Quick answer
Standard subway tile (3×6") at 1/16" gap: ~0.04 kg/sqft (4 kg per 100 sqft). 600×600 mm floor tile at 3 mm gap: ~0.05 kg/sqft. Always order 10% extra.
Tile & gap details
Grout needed
5kg
For 100 sqft at 3 mm gap
Tile size600 × 600 mm
Gap width3 mm (1/8 inch)
Coverage rate~0.05 kg/sqft
Base requirement~5 kg
+ 10% wastage~5.5 kg
Bags needed2 × 5 kg bags
How grout quantity is calculated
Grout fills the joints between tiles. The volume of joints depends on tile size (smaller tiles = more joints per area), gap width and tile thickness. The calculation gives you joint volume, then converts to grout weight.
Formula: Grout (kg) = ((tile_L + tile_W) ÷ (tile_L × tile_W)) × gap × thickness × area × density
Coverage by tile size (1/8" gap, 8mm thickness)
| Tile size | Per sqft | For 100 sqft |
|---|---|---|
| 3"×6" subway | ~0.04 kg | ~4 kg |
| 12"×12" (300mm) | ~0.06 kg | ~6 kg |
| 12"×24" (300×600mm) | ~0.04 kg | ~4 kg |
| 24"×24" (600mm) | ~0.05 kg | ~5 kg |
| 24"×48" (600×1200mm) | ~0.03 kg | ~3 kg |
| 32"×32" (800mm) | ~0.04 kg | ~4 kg |
Standard gap widths
| Gap | Best for |
|---|---|
| 1/16" (1.5 mm) | Rectified large-format tiles, premium look |
| 1/8" (3 mm) | Standard floor and wall tiles — most common |
| 3/16" (5 mm) | Natural stone, slate, irregular edges |
| 1/4" (6 mm) | Handmade, terracotta, rustic tiles |
| 3/8"+ (10 mm+) | Decorative wide-joint design |
Tips for grouting
- Always order 10% extra — for spillage, mixing waste and patch repairs.
- Mix only what you can use in 30 minutes — grout starts curing as soon as it's mixed with water.
- Use spacers matching your gap width to ensure consistent joints.
- Wipe off excess before it cures — within 15-20 minutes of application.
Frequently asked questions
How much grout for subway tile?
For 100 sqft of standard 3×6 inch subway tile with 1/16 inch grout gap, you need approximately 4 kg of grout. With 1/8 inch gap, increase to ~7 kg. Always order 10% extra.
What is standard grout gap width?
Standard gap widths: 1/16 inch (1.5 mm) for rectified large-format tiles, 1/8 inch (3 mm) for most floor tiles, 3/16 inch (5 mm) for natural stone, 1/4 inch (6 mm) for handmade or rustic tiles.
How is grout quantity calculated?
Grout volume = (tile_length + tile_width) ÷ (tile_length × tile_width) × gap_width × tile_thickness × area. The formula calculates the total joint volume between tiles, then converts to grout weight (~1.6 kg per litre).
Sanded vs unsanded grout?
Sanded grout for joints wider than 1/8 inch — sand prevents shrinkage cracking. Unsanded grout for narrower joints (1/16 to 1/8 inch) and polished surfaces where sand could scratch.
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