What follows is very long. Sorry I don't have time to make it shorter!

The word "classic" in classic subway tiles answers the question. Subway tiles are always a good choice. They have stood the test of time for over 100 years, and will continue to do so. Personally, I love them. But that doesn't mean you have to love them, too.

4x4 is more old-school than 5x5, in my opinion. This, too, can be considered a classic look. I think walls full of white 4x4 (or 5x5) look clinical. Some people feel that walls full of white subway tile look clinical. How do each of these looks make you feel?

If you buy something "on trend" for 2026, the chances are good that it will feel dated to you by the time you get around to renovating the rest of your bath. Decide whether you want classic or trendy. Those are two entirely different approaches. One is not inherently better than the other, but one may well be more useful for your needs and desires than the other.

What do you imagine you would like to replace your beadboard and "cottage-style" vanity with? What goes with those replacements in your mind's eye?

Why are you replacing only the tub and surround now, and planning to leave the rest of the bathroom as-is for at least a decade? (I'm not saying you shouldn't do this; I'm encouraging you to think it through thoroughly, as the answer to "why" may affect your tile choices.)

Do you want only white tile? Or white with trim in a different color? Will you be able to replace your tub without changing your flooring? What will you do if turns out you have to change the flooring?

What does the word "classic" mean to you? What period and/or style of design and/or architecture does classic call up to your mind's eye?

If you don't have a collection of photos exemplifying what you like/aspire to, this is a good time to create one. Houzz has an Ideabook feature that I used for that purpose. Alternatively, you can download pictures to a folder on your hard drive, or save them in a note-taking app or a photo app, use a Pinterest board—any way that works for you, just get them all in one place and figure out which pictures make you happiest, and why. That can help you to pick tiles for your bath that you won't be sick of in 10–15 years. It worked for me. My own, very ambitious goal was to not be tired of any of my finishes for 25 years. I'm only about four years in (maybe it's closer to six? I've lost track!) but every time I enter my home, or enter one room from another, it makes me happy. I hope at least one of my suggestions can help you achieve the same for yourself.

Not all subway tiles are created equal and given the cottage style of your bathroom and only updating in years to come, it might be a good choice (it’s proven to be more timeless than most).

Results will vary depending on shape/size/texture, pattern and grout.

I find that looking on line is really helpful as there is nothing better than visuals.

Consider the vanity, floor tiles and bead board, as they are big factors.

I think less grout lines the better. We turned a small bathroom into a wet room for the most part and used large 6x12 tile for the walls. Given the popular back splash for kitchens is solid material I think larger tiles or solid in a shower would be my go to if I were doing it again. If you like the 5x5 go for it. Check out Sarah Richardson's showers. She puts a ton of design/color/pattern in hers using standard 5x5s.

Thank you amystoller for your lengthy reply! The bathroom is "only" 15 years old and still looks good, but the tub/shower was not replaced at that time and really needs to be now. Hence why we are just replacing the tub. So I'm really just looking for something super basic that will be good enough when we do renovate the whole thing. And yes, arcy_gw, I'm leaning towards something larger format, I appreciate seeing your 6x12s in the photo.

In my son’s bathroom we ran subway tiles vertically in his shower. Love it. In my girls bath their tiles are larger format and with character and I also love them.

"Subway tile" is such an ambiguous name. What it says to me is a plain white 3x5" tile that was used in big city subways like NY in the early part of the 20th century. What many people think is that any rectangular tile in any color is subway tile, which couldn't be farther from the truth.

The question is what do YOU want your bathroom to look like? If you really like something now, and ignore "trends" then chances are you'll love it for a very long time.

My philosophy is if the style works with your house style, then you can't go wrong--it will always look appropriate. Putting an Edwardian bath in a split level home doesn't work, and a modern bathroom in a Colonial revival doesn't work either.

White will always work with anything else, whether tile, toilets, sinks or tubs. If you like rectangular tiles, go for it. You can also use square, arabesque, fishtail, picket, or any other shape you like.

This bathroom is in my 1920s colonial revival home, and was done in 1996. It looks just as good today as it did when first finished. And I still love it.

""Subway tile" is such an ambiguous name. What it says to me is a plain white 3x5" tile that was used in big city subways like NY in the early part of the 20th century. What many people think is that any rectangular tile in any color is subway tile, which couldn't be farther from the truth."

Amen.

Also, classic means something very different from basic, at least to me.

A white 3x5 subway tile with a thin to medium groutline in an non-contrasting grout is the little black dress of a tub/shower combo. You can completely transform the look of it from cottage to modern and everything in between depending on the shower curtains or door you use, your plumbing fixtures, paint color, vanity and accessories. You can buy inexpensive or expensive ones and they will look very similar.

We moved into a home with a primary bathroom that had white subway tiles 2/3rd up the walls and in the whole shower tub combo. It was a very modern bath with contemporary light fixtures, contemporary wall hung sink, and very modern circular mirror. I swapped the hardware on the vanity, hung a rectangular antique wood mirror, hung a brass vanity lighting, and a new shower curtain. Complete transformation. Same tile.

Large format tiles can look lux or super trashy and cheap depending on the tile. Show me a large format tile that is going to look less trendy and more enduring than the 3x5 white subway tile and I will change my mind.

I renovated bathrooms in my home that had 4.25 x 4.25 tiles for showers and shower/tub combo surrounds. The surrounds were in great shape (and I had zero issues having white grout lines - no mold/mildew scrubbing that so many people discuss). I knew that I would be gutting the primary bathroom - but was considering keeping the the white tiles in the guest bathroom that had the tub/shower combo. However, once I changed the bathroom floor + added a new vanity +toilet + mirror + light fixture, I decided to change the tile surround also.

My tiles were installed in the typical stacked pattern - to me that looks "dated" (unless they are in an older home - this house was built in 1996). I think that if the tiles had been in a staggered pattern, I probably would have kept the surround. The stacked pattern reminded me of graph paper.

As @Maureen as shown above, many tiles are called "subway tiles" - even though they aren't 3x6 in size. I think that the 3x6 size will never be "dated" - they just don't look new/fresh currently because so many people went on a subway tile craze about 10 years ago. People started installing similar tiles that were larger than 3x6 + used different installation patterns to change things up a bit.

All of the bathroom photos that Maureen posted above still look nice to me - and I bet that they weren't installed recently. I think that a 3x6 subway tile in a running bond pattern is a pretty safe choice for something that won't look dated because they've been around for a long time (they've just been more popular at different times - but it seems they always come back around). If I would have had 3x6 white subway tiles in my guest bathrooms, I doubt that I would have spent the money to replace the surrounds.

FYI - I replaced the white 4.24 x 4.25 stacked tiles with white 2.5 x 8 tiles (Bedrosian Cloe tiles in white have some variation in color which provides some extra interest vs. a regular solid white tile) - I had them installed in a vertical stacked pattern.