Introduction
This Mapei grout calculator tells you how much grout you need for your tile job. You pick your Mapei product, type in your tile size, joint width, and area, and it gives you the number of bags to buy.
Buying grout is easy to get wrong. Too little means a second trip to the store in the middle of the job. Too much means wasted money and leftover bags. The calculator sizes the order so you buy the right amount the first time.
It works with five Mapei grouts: Ultracolor Plus FA, Keracolor FF, Kerapoxy, Kerapoxy Easy Design, and Kerapoxy CQ. Each one has its own density and joint width limits, and the calculator uses the right numbers for the product you choose. It also warns you if your joint is too wide or too narrow for that grout.
You can work in inches and square feet or in millimeters and square meters. Results always show both kilograms and pounds. You also get a cost range, a joint diagram that changes with your numbers, and a full step-by-step breakdown so you can check the math yourself.
How to use our Mapei Grout Calculator
Tell us your tile size, your job area, and your joint size. The calculator shows how much Mapei grout you need in kg and lb, how many bags to buy, and a cost range.
Unit System: Pick Imperial (sq ft and inches) or Metric (m² and mm). All the boxes change over for you.
Select Your Mapei Grout: Click the grout product you plan to use. Each card shows the bag sizes and the best job type for that grout.
Tile Size Preset: Choose a common tile size from the list. Pick "Custom" if your tile is not shown, or just type your own size.
Tile Length: Enter how long one tile is. Measure the tile itself, not the room.
Tile Width: Enter how wide one tile is. Square tiles use the same number as the length.
Tile Thickness / Joint Depth: Enter how thick your tile is. This is how deep the grout fills the joint.
Area to Grout: Enter the total tiled area only. Leave out cabinets, tubs, and any part you will not tile.
Grout Joint Width: Enter the space between your tiles. Stay inside the range shown for the grout you picked.
Overage / Waste Factor: Add extra grout for spills and mix-ups. Use 10% if you are skilled, or 15% to 20% for a first-time job.
Bag Size: Choose the bag size you want to buy. Only bags made for your chosen grout will show up.
Press Calculate to see your bag count, total weight, cost range, and the full math steps. Press Reset to start over.
What Is Mapei Grout?
Grout is the material that fills the small gaps between tiles. Those gaps are called joints. Grout locks the tiles in place, keeps water and dirt out, and makes the floor or wall look finished. Mapei is one of the biggest grout brands in the world, and it sells grout in bags of dry powder or in two-part epoxy kits.
Cement Grout vs. Epoxy Grout
Mapei makes two main kinds of grout, and they are used for different jobs.
- Cement grout (like Ultracolor Plus FA and Keracolor FF) is mixed with water. It is easy to use, cheap, and good for most homes, including kitchens, bathrooms, hallways, and outside patios.
- Epoxy grout (like Kerapoxy, Kerapoxy CQ, and Kerapoxy Easy Design) is mixed from resin and hardener. It costs more and sets fast, but it fights stains, acid, and harsh cleaners. Use it on countertops, in kitchens for restaurants, labs, pools, and busy shops.
What Changes How Much Grout You Need
Grout use is not based on floor area alone. Five things matter:
- Tile size: Small tiles have more joints in the same space, so they eat far more grout. Big tiles need much less.
- Joint width: A wider gap holds more grout. Going from 3 mm to 6 mm can double the amount.
- Tile thickness: The joint is filled all the way down, so thicker tiles mean deeper joints and more grout.
- Area: Measure only the tiled surface, not the whole room.
- Waste: Some grout is always lost in the bucket, on the sponge, and on the float. Add extra.
Density Matters Too
Grout is sold by weight but fills a space by volume. Cement grout weighs about 1.60 kg per litre. Epoxy grout is heavier, about 1.80 kg per litre. That means the same joints need more kilograms of epoxy than cement.
Picking a Joint Width
Each Mapei product works in a set range of joint widths. Ultracolor Plus FA covers 2 mm to 20 mm. Keracolor FF is a fine grout for thin joints of 2 mm to 6 mm. Epoxy grouts fit roughly 1 mm to 15 mm, depending on the product. Using grout outside its range can crack, shrink, or look uneven. Rectified tiles often use 2 mm to 3 mm joints, while stone, brick look, and outdoor tiles use wider ones.
Waste and Extra Bags
A 10% waste factor works for skilled tilers. First-time DIY jobs should use 15% to 20%. Uneven tiles, rough tile edges, and stopping and starting all waste grout. It is smarter to buy one extra bag than to run short, since a new batch or a new dye lot can dry a slightly different shade.
Handy Tips
- Mix only what you can use before it sets. Cement grout stiffens in about 30 to 45 minutes, and epoxy even faster.
- Clean the joints before grouting. Loose adhesive takes up space that grout should fill.
- Do not grout corners or edges where walls meet floors. Use flexible silicone there.
- Buy all your bags at the same time and check that the colour code matches on each one.