Grout Calculator

Estimate grout-joint volume and packages using your tile geometry and manufacturer coverage.

Your tile project

1. Project area

Use the total covered footprint, including joints; exclude openings.

2. Tile size

Use face dimensions; decimals or simple fractions such as 1/2.

Actual size may differ from the nominal box label.

3. Grout joint

Choose or type 1/16, 1/8, 3/16, 1/4, or a decimal.

Depth actually filled with grout, often related to tile thickness; exclude space already occupied by mortar.

Editable example for mixing loss, cleanup, uneven joints and touch-ups. Not a mandatory standard.

4. Grout package (optional)

Find this on the manufacturer's coverage chart for your specific grout. Use the coverage that matches your tile size and joint width. If you don't know it, leave this blank — we'll still calculate grout volume.

Label only, such as your product and bag or tub size; no yield is assumed.

Used only with coverage. Material cost excludes tax, shipping and tools.

How it works

A repeating tile-and-joint cell has area (tile length + joint width) × (tile width + joint width). The joint fraction is [joint width × (tile length + tile width) + joint width²] ÷ cell area. Multiply that fraction by project area × 144 and filled joint depth to get cubic inches. Divide by 1,728 for cubic feet. Shared joints and crossings are counted once.

Add your planning allowance to both volume and project area. With manufacturer coverage supplied, exact packages = allowance-adjusted area ÷ coverage per package. Round up to whole packages. If a price is supplied, cost = whole packages × price.

Assumptions and useful information

This models rectangular tiles, repeating joints and a uniform filled depth. Project area includes tile faces and joints. It approximates a large repeating grid rather than counting perimeter joints. Beveled edges, irregular patterns, mesh mosaics and uneven depth can change the actual volume. Exclude movement or perimeter joints filled with sealant.

Different grout products and package sizes have different yields. Match your manufacturer’s chart to the actual tile dimensions, joint width and filled depth; ask the manufacturer if your configuration is not listed. Changing geometry here does not automatically update the coverage you entered. Avoid adding the same allowance twice if your selected coverage already includes one.

The optional allowance is a planning choice, not an industry-mandated value. This tool estimates material quantity; it does not choose grout chemistry, permitted joint widths or installation methods. Follow product instructions.

If you still need to determine your tiled area or tile quantity, use the RockUtility Tile Calculator first.

Examples of product-specific coverage guidance: CUSTOM grout coverage tables and MAPEI product calculators. Use the current chart for the product you buy.

Estimate only. Confirm coverage, package size and installation requirements with your grout manufacturer before purchasing.