How do you measure a tub for a shower conversion?
Measure the alcove stud to stud, not the inside of the finished walls. Take the length and width at the bottom, middle and top and use the smallest number. Then note the drain side and measure the path the kit has to travel to reach the bathroom.
The most common ordering mistake is measuring the finished wall instead of stud to stud, the distance between the framing behind the tile or surround. A standard shower can't be returned, so ten minutes with a tape measure protects your project.
- ✓ Know your alcove size before you shop
- ✓ Match the drain side the first time
- ✓ Confirm the kit gets through your doors
- ✓ Order with confidence
What is a tub-to-shower conversion?
A tub-to-shower conversion replaces your bathtub with a walk-in shower in the same alcove. A conversion kit arrives sized for that space, so the measurements you take decide which kit fits. Those measurements are taken stud to stud, because the kit's walls go on the framing, not on the old tile or surround.
Measure Stud to Stud, Not the Finished Walls
The tub label tells you what was sold. The framing tells you what will fit.
Stud to stud decides the kit.
Stud to stud means the distance between the wall framing behind the tile, surround or drywall. The old wall surface comes off and the kit goes on the framing, so tile, surround and drywall are not what the kit is built around. Walls are also rarely perfectly square or flat. A 60 x 30 or 60 x 32 label is a starting point, so measure stud to stud and compare.
How to Measure Your Tub Alcove Stud to Stud
You need a tape measure, a pencil and about ten minutes.
Measure the length stud to stud
Measure along the back wall from the stud at one end to the stud at the other, not from tile to tile. Do it at the bottom, middle and top, because walls can lean or bow.
Measure the width stud to stud
Measure from the back wall studs to the front framing of the alcove, again at three heights. Write down the smallest number you get.
Note the drain side
Stand facing the tub. Is the drain to your left, to your right or centered? Kits are built for a specific drain position, so this matters.
Take each measurement at three heights and use the smallest number.
Example: if stud to stud reads 60, 59-3/4 and 60-1/4 inches, plan around 59-3/4.
Note: This is a planning aid, not a guarantee. Always verify the fit against the manufacturer's spec sheet and call us before you order.
Measure the Path Into the Bathroom
A kit that fits the alcove still has to get there.
| Where | What to measure | Why it matters |
|---|---|---|
| Front door and hall doors | Narrowest width and height of each opening | The kit has to pass through every one |
| Hallways and turns | Width, plus how tight the turns are | Long pieces need room to pivot |
| Stairs | Width, ceiling height and landings | Carrying up or down changes what fits |
| Bathroom door | Width and height of the opening | Often the tightest point on the path |
Match Your Numbers to a Kit
Once you have your stud-to-stud measurements, shop by size or by the features you need.
Shop by size
Most tub alcoves are about 60 inches long stud to stud. Browse 60 x 30, 60 x 32, 60 x 34 or 60 x 36 kits, or see every tub-to-shower conversion kit.
Shop by feature
Want an easier step in? Look at curbless showers. Want a place to sit? See walk-in shower kits with a built-in seat.
Tub-to-Shower Measuring Checklist
Work through these ten points and write the numbers down before you shop.
Numbers in hand?
Send us your stud-to-stud size, drain side and narrowest doorway and we will confirm the kit with you. Measure twice, order once.
The Bottom Line: What Do You Need to Measure?
Three things: stud to stud, the drain side and the path in.
Get those right and the kit you choose will fit your framing and your home.
Stud to stud
Length and width between the framing, measured at three heights. Use the smallest number.
The drain side
Stand facing the tub and note left, right or centered.
The path
Narrowest doorway, hallway turns and stairs between the door and the bathroom.
Frequently Asked Questions About Measuring for a Tub-to-Shower Conversion
Click a question below to expand the answer.
How do I measure my tub alcove for a tub-to-shower conversion kit?
Measure the alcove stud to stud, not the inside of the finished walls. Measure the length along the back wall and the width from the back wall to the front framing, each at the bottom, middle and top, and use the smallest number. Then note the drain side, the faucet wall and the path the kit has to travel into the bathroom.
Is the size on my tub the same as my alcove size?
Not always. Tubs are sold by nominal size, and the finished wall surface is not what a kit is built around. Kits also have nominal names, so compare your stud-to-stud measurements to the actual dimensions and rough-in information on the spec sheet for the kit you are considering.
Will a conversion kit fit through my doorway and hallway?
Measure the narrowest width and height along the whole path, including door frames, turns and stairs. Multi-piece kits are easier to carry through tight spaces than one-piece units. If anything is close, call us before you order.
Can I return a shower if I measured wrong?
Standard showers and bases are Made-Upon-Order and can't be returned. That is why we say measure twice, order once, and why our product specialists will verify your dimensions with you before you order.
How long until my kit ships?
Lead time varies by product and is listed on each product page. Quick-Ship kits ship the next business day.
What warranty comes with a shower kit?
Warranty length and terms vary by product and are listed on each product page, including the 30-year manufacturer limited warranty on many EZ Able® showers.
Need Help Planning Your Tub-to-Shower Conversion?
EZ Able® can help you compare kits based on your stud-to-stud size, drain side and the entry you want.
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Posted by Jody Fisk, President of EZ Able®. Licensed Michigan residential builder since 1991.
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