Backsplash and sidesplash are different pieces
A backsplash runs along the back of the vanity, the full width, against the wall behind the basin. A sidesplash is the short vertical return at the end of a counter, where the top meets a side wall.
Both are in this range and they are not interchangeable. A vanity in an alcove, with walls at both ends, needs a backsplash and two sidesplashes; a vanity with one open end needs a backsplash and one.
The sizes are widths, not areas
The size field here reads 30, 36, 48, 60 and 72 inches, which are vanity widths rather than tile dimensions.
A splash is cut to match the top it belongs to, so the number to look for is the width of the vanity itself. Vanities, single vanities and double vanities carry the cabinets those widths correspond to.
Quartz and engineered marble
Quartz leads the materials here, with engineered marble behind it and a little natural marble, granite and slate.
Both of the leaders are manufactured stone: crushed mineral bound in resin, pressed into slabs. That matters for a splash specifically, because a manufactured material repeats exactly, so the strip on the wall is the same color as the top in front of it with no variation between them. A natural stone splash and a natural stone top can differ visibly.
Why a splash exists at all
The junction between a countertop and a wall is where water collects, and it is the part of a bathroom people lean over.
A splash covers that junction in the same material as the top, so there is one line to deal with instead of two and no change of material at the point water actually reaches. The alternative is tiling the wall down to the counter, which is a different job and a different look.
The height is a decision too
A standard splash is around four inches high, which covers the junction and stops there. Taller versions run up behind the basin to a mirror or a shelf.
Four inches is enough for the job it was invented for and low enough that the wall above stays paint. A taller splash starts to behave like a tiled wall while still being a single piece of stone, which is the most expensive way to cover a wall and occasionally the right one when the slab is the point of the room.
Splash or tiled wall
These are the two ways to finish the wall behind a basin and they produce different bathrooms.
A splash is four inches or so of stone and the wall above it is paint. A tiled wall carries the surface up to a shelf, a mirror or the ceiling. The splash is the quieter and more usual choice, and it is the one that makes sense when the countertop is the material worth looking at.
Thickness and the return
The pieces here that publish a figure sit around 0.79 inch, which is 20 millimeters, the standard slab thickness these tops are cut from.
That is the depth the splash will stand off the wall, which is worth knowing where a mirror, a cabinet or a light sits directly above it. Bathroom accessories and bathroom faucets cover the fittings that share that wall.
