Work out tile grout quantity instantly with clear inputs, formula shown and shareable results.
Grout volume is total joint length times joint width times depth. Joint length per square metre is 1/tile length plus 1/tile width, so small tiles need far more grout than large ones — mosaic can use ten times the grout of a large format tile.
Grout quantity
joint length per m2 = 1/L + 1/W; volume = length x width x depth; mass = volume x 1.6 kg/L
Grout follows the perimeter of every tile. Halving the tile size doubles the joint length per square metre.
2-3 mm for rectified porcelain, 3-5 mm for ceramic, and wider for handmade or natural stone where size varies.