Estimate tile grout or CMU/block grout fill volume, weight and bags — metric or imperial.
Joint depth is usually close to your tile's thickness. Enter 0 joint width if you're using a butt/rectified tight-joint layout (grout needed will be zero). Tile size presets are common sizes for a quick start, not a universal standard - dimensions are always shown so you can confirm or adjust them.
Grout type presets set a typical planning-estimate density for that grout family - they are not authoritative for any specific brand. Density stays fully editable; adjust it to your specific product for the most accurate weight estimate.
Enter your specific product's bag weight from its label. Leave at 0 to see total weight only, without a bag count.
Optional cross-check: enter your product's stated coverage per bag (from its technical data sheet, for your specific joint size) to compare against this calculator's geometric estimate.
Enter a price to see an estimated cost for this mode's bags directly in the results.
| Item | Value |
|---|
Choose Tile Grout for tiled floors and walls, or CMU / Block Grout for filling concrete masonry unit cores. On the Tile Grout tab, enter your tiled area, tile size (or pick a size preset), and joint width/depth. On the CMU tab, choose a calculation method and enter your core dimensions. Confirm the density and bag weight fields against your specific grout product for an accurate bag count, optionally enter a price per bag for an immediate cost, then check the Cost tab for either material's cost or a side-by-side comparison.
Grout fills the joint space between tiles, so the volume needed is the total joint area (a function of tile size and joint width) multiplied by joint depth. This is a geometric grout estimate, not a manufacturer coverage figure.
This is a purely geometric calculation based on your actual tile and joint dimensions - it isn't tied to any single manufacturer's coverage chart, which is why the result changes correctly with tile size: smaller tiles have proportionally more joint length per square foot, so they need more grout for the same joint width. If your product's technical data sheet states a coverage per bag, enter it in the optional cross-check field to compare against this geometric estimate.
Filling concrete block cores for structural or code reasons is a different calculation - simple volume, not joint geometry. Choose Core/cell volume to count individual cores, or Continuous vertical cells for a column of cells filled in one lift across multiple courses - both use the same underlying volume formula.
Core dimensions vary by block size, so measure your specific block's core opening (or check the manufacturer's specification) rather than assuming a standard size. This is a material-quantity estimate only and does not check reinforcement clearance, lift height limits or structural design.
Both tabs convert purchase volume to weight using a density figure you can adjust, then to a bag count using your product's bag weight. Grout density varies meaningfully by type (sanded, unsanded, epoxy, or coarse CMU fill grout), so the Grout Type selector offers typical planning-estimate densities you can override - your product's bag will state its own coverage or weight. Enter a price per bag directly on the Tile Grout or CMU/Block Grout tab for an immediate material cost, or use the Cost tab to view either material's cost or a comparison; tile grout and CMU/block grout are normally alternative systems, not materials purchased together.
Tile grout. A 10 m² floor with 300×300mm tiles, a 3mm joint width and 8mm joint depth: joint area fraction ≈ 1.97%, base grout volume ≈ 0.001577 m³. Applying 10% waste gives a purchase volume of 0.001734 m³ (1.73 L), weighing about 2.77kg at 1600 kg/m³, needing 1 bag at 5kg per bag.
CMU grout. 40 cores at 150×150×190mm each: base volume = 0.171 m³. Applying 10% waste gives a purchase volume of 0.1881 m³ (188.1 L), weighing about 395kg at 2100 kg/m³, needing 14 bags at 30kg per bag.
The most common mistake is ignoring tile size when estimating grout - the same joint width needs noticeably more grout for small-format or mosaic tile than for large-format tile, since small tiles have far more joint length per square foot. Another frequent error is confusing tile grout with CMU/block grout, which are entirely different calculations (joint geometry versus core volume) despite sharing the word "grout." It's also worth double-checking joint depth - it should reflect how deep the joint actually is, which is usually close to tile thickness but not always identical to it.
This calculator estimates material quantity from the dimensions and density you enter. It is not tied to any specific manufacturer's coverage chart or product line, does not account for grout haze/cleanup product, sealer, or spacers, and does not check CMU reinforcement clearance, lift height limits, grout consolidation requirements or structural design - confirm your specific product's coverage and your project's engineering requirements separately for structural masonry work. Density and bag weight defaults shown are typical planning estimates only. Tile size and grout type presets are convenient starting points, not universal standards - dimensions and density are always shown so you can confirm or adjust them.
Grout fills the joints between tiles, so the volume needed depends on your tiled area, tile size, and your joint's width and depth. Smaller tiles or wider joints need proportionally more grout since there's more joint area relative to tile area. Use the Tile Grout tab above with your tile and joint dimensions for an automatic estimate.
Yes significantly - smaller tiles have proportionally more joint length (and therefore more joint area) per square foot of coverage than larger tiles, so a mosaic or small-format tile job needs considerably more grout than the same area in large-format tile with the same joint width.
Sanded grout contains fine sand and unsanded doesn't - sand adds strength and reduces shrinkage in wider joints, while unsanded is smoother and gentler on polished or delicate tile surfaces. Many manufacturers recommend sanded grout above roughly 1/8 inch (3mm) and unsanded below it, but this threshold varies by brand and product line, so always check your specific manufacturer's joint-width recommendation. The two also have somewhat different densities - use your specific product's density if you know it for a more accurate weight estimate.
CMU grout fill volume is the number of cores/cells being filled multiplied by the volume of one core (core length × width × height), plus a waste allowance. This calculator offers a Core/cell volume method for individual cores and a Continuous vertical cells method for multi-course pours filled in one continuous lift - both use the same underlying volume calculation. This is a different calculation from tile grout - use the CMU / Block Grout tab above.
Core/cell volume treats each core as an individual fill with its own height, useful when you're counting discrete cores. Continuous vertical cells is for pours where a column of cells spans multiple courses in one continuous lift - you enter the number of cell columns and the total fill height instead of counting each core separately. Both use the same core length × width × height math underneath.
Coverage per bag varies by brand, tile size and joint dimensions, so there's no single figure that applies across products. This calculator computes the grout volume and weight needed from your actual tile and joint dimensions, then converts to bags using the bag weight you enter from your specific product. If your manufacturer states a coverage figure, enter it in the optional cross-check field on the Tile Grout tab to compare it against this geometric estimate.
Grout cost depends on grout type (sanded, unsanded, epoxy), brand and local prices. Enter a price per bag directly on the Tile Grout or CMU/Block Grout tab for an immediate cost estimate, or use the Cost tab to view either material's cost or a side-by-side comparison; installation labour and tools are priced separately.
No - it uses a general geometric calculation based on your tile/joint or block dimensions, with density and bag weight fields you can adjust to match your specific product. Optional tile size and grout type presets are provided as convenient starting points, not universal standards. It does not use or assume any particular manufacturer's coverage chart.
The volume calculation (based on joint dimensions) is the same, but epoxy grout typically has a different density and is sold in different unit sizes than cementitious grout - select Epoxy from the Grout Type list for a starting density, or adjust the density and bag weight fields on the Tile Grout tab to match your specific epoxy product.