How much grout for subway tile backsplash?
1 kg of grout for a subway tile backsplash, at the settings most people start with. Below the calculator are the same numbers for the alternatives you are likely to choose, and what each one does to the total.
Reviewed · Method: measured dimensions, industry coverage rates, rounded up to real package sizes · How the numbers are calculated
Values are pre-filled for this page. Change anything and hit Recalculate.
The answer, and what it is made of
18 sq ft of 3 x 6 tile with a 2 mm joint at 6 mm deep needs 1 kg of grout — one of the 10 kg bag. Buy the full bag even if you only need part of it: opened grout takes up moisture from the air and sets lumpy within weeks.
Planning figure for everything on that list: $19 to $45, with $29 as the realistic middle for the products most people actually buy. These are estimates for budgeting, not quotes. Prices move by region and by season, and the middle figure assumes a mid-range product rather than the cheapest thing on the shelf.
Joint width does most of the work here: 1 kg at a 1/16 in joint joint becomes 3.1 kg at 1/4 in joint. The joint is a volume, not a line, so doubling its width roughly doubles the grout for the same floor.
What changes if you change one thing
| Change the joint width | You buy |
|---|---|
| 1/16 in joint, standard subway | 1 kg |
| 1/8 in joint, handmade look | 1.6 kg |
| 1/4 in joint, beveled tile | 3.1 kg |
Every row is a live calculation, not an estimate. The shaded row is what this page defaults to.
What goes in the cart
| Item | Quantity |
|---|---|
| Grout, 10 kg bag | 1 bag |
| Grout float (rubber face) | 1 |
| Grout sponge, large pore | 2 |
| Sealer, 1 qt (for porous grout) | 1 qt |
| Bucket + mixing paddle | 1 set |
Do not mix the whole bag. Mixed grout has a 20 to 30 minute pot life. Mix in batches sized to what you can float and wipe in that window, or you will be scraping rock out of the joints.
What this size actually changes
An 18 sq ft backsplash in 3x6 subway has around 72 linear feet of joint — more than a 100 sq ft floor of 12x24. That is why the grout quantity per square foot is so high on small tile, and why this page needs about 1 kg where a much larger large-format floor needs three.
Figure. subway tile backsplash: 12 x 1.5 ft. Measure the finished surface, not the room walls — the area between skirting or cabinet faces is the area you pay for.
How the quantity is worked out
Grout quantity is driven by the joint, not the floor. Two jobs with the same square footage can need three times the grout if one uses a 1/4 in joint and the other a 1/16 in joint, because the volume of the gap scales with joint width and depth together. That is why grout bags carry a yield chart instead of a single coverage number.
Depth matters as much as width. A 3/8 in deep joint takes twice the grout of a 3/16 in joint at the same width. On a floor with a deep bed, you are filling a channel, not wiping a line. Cementitious grout also shrinks slightly as it cures, so the joint you fill is not quite the joint you end up with.
How to measure this job
A backsplash is measured in linear feet along the counter, not in square feet of room. Measure the counter run from the end of the cabinet to the end of the cabinet, then measure the height from the counter to the underside of the upper cabinets. That is normally 18 in, but it is 24 in where the counter runs under a window, and it is the full wall height if you are tiling up to the ceiling.
Then subtract the range hood and any window, and add the returns at each end — the short piece that turns the corner is easy to forget and always needs its own cuts. For the calculator, enter the length in feet and the height in feet: 18 in is 1.5 ft.
Mistakes that cost real money
Buying grout by square footage instead of by joint volume
A 10 lb bag does not cover a fixed area. It covers a volume. Two floors of the same size can differ by a factor of three depending on joint width and depth, so the bag count has to come from the joint dimensions, never from the room size alone.
Measuring the wall instead of the counter run
The backsplash follows the counter, and the counter stops where the cabinets stop. Measuring the full wall adds the space beside the fridge and the gap at a doorway, which is tile nobody sees and cuts nobody planned.
Using sanded grout on a 1/16 in joint
Sanded grout will not pack into a joint that tight and leaves a gritty, uneven line. Unsanded grout is specified for joints under 1/8 in, and it is also less likely to scratch a glazed or hand-made tile surface.
Grouting before the adhesive has cured
Thinset needs 24 hours before grout on a wall, longer in a cold room. Grouting early pulls moisture out of the adhesive and the tile lifts at the edges, which on a backsplash shows as a shadow line under the cabinet.
Frequently asked questions
How many square feet does a 10 lb bag of grout cover?
There is no single number, because it depends on tile size, joint width and joint depth. A 10 lb bag on 12x24 tile with a 1/8 in joint covers roughly 100 sq ft. The same bag on 3x6 subway tile with the same joint covers far less, because the joint length per square foot is much higher.
How much tile do I need for a kitchen backsplash?
A typical 12 ft run at 18 in high is 18 sq ft, so about 20 sq ft with waste — four 5 sq ft boxes of subway tile, or roughly 30 sq ft of mosaic sheet. Add 10 percent, and more if you have several outlets or a window to tile around.
How much grout for a subway tile backsplash?
About 1 kg for 18 sq ft with a 1/16 in joint, so a 5 kg bag does several backsplashes. Most people buy far too much here because they use floor-area rules on a wall of small tiles.
Should subway tile grout be white or grey?
White is the traditional look and hides nothing; grey is more practical and reads as deliberate. On a kitchen splash, white grout behind a hob will discolour within a year. A light grey is the usual compromise and matches most white tile without looking dirty.
What will the materials for this cost?
A planning range of $19 to $45 for everything in the shopping list, with $29 as the realistic middle. That is materials only: it excludes labour, delivery, tool hire and disposal of the old surface. Treat it as a budgeting figure, not a quote.