What size shower curtain do you need?

Shower curtain sizes by shower type

How to measure, in two numbers

Width: measure the rail from end to end, then multiply by about 1.5. A curtain the same width as the rail hangs flat and tight, which looks wrong and leaves gaps at the ends when you push it aside. On a standard 60-inch tub rail, 72 inches of curtain is that 1.5× allowance already built in.

Length: measure from the bottom of the curtain rings — not the rail itself — down to the floor, then subtract two inches. Two inches of clearance is the figure to aim for: enough that the hem does not sit in puddles and wick water or grow mildew, little enough that water does not escape under it.

A liner should be the same length as the curtain or an inch shorter, never longer. The liner goes inside the tub, the curtain stays outside, and a liner that reaches further down than the curtain just channels water onto the outside of it.

Curtain, liner, or both?

A liner is the waterproof layer that hangs inside the tub. A curtain is the decorative layer outside it. You need the waterproof layer; the decorative one is optional.

• Liner only is perfectly functional and the cheapest route. It looks like what it is.
• Waterproof fabric curtain only — one layer doing both jobs. In a small bathroom this is the best answer: less bulk inside the shower, machine washable, and it looks like a furnishing. Add a weighted hem or hem magnets or it will cling to you.
• Both is the traditional setup, and worth it only if you want a specific decorative curtain. Two layers in a narrow stall is a lot of fabric.

Our fabric vs plastic liner comparison goes through the trade-off in more detail, including why PEVA gauge matters.

Rings, hooks and the grommet question

Twelve rings is standard, matching the twelve grommets on a standard curtain. Two details are worth a sentence each. Metal grommets beat punched holes — punched holes in thin plastic tear out within a year, usually the end one first. Roller or glide hooks cost a few dollars more than plain rings and make the curtain genuinely pleasant to pull, which matters in a tight bathroom where you are reaching across yourself to close it.

If you are renting and the rail is a fixed bar, you cannot change much. If it is a tension rod, make sure it is rated for the span — a rod at the limit of its range drops under the weight of a wet liner, usually at six in the morning.

If the curtain you already have is the wrong size

Three common situations, and what actually fixes each:

• Too long, pooling on the floor. Move it up rather than cutting it: use S-hooks or rings with a shorter drop, or raise the tension rod. If you do shorten a plastic liner, cut from the top and punch new holes with a reinforcing eyelet kit — cutting the weighted hem off the bottom is what makes a liner billow inward.
• Too short, water escaping underneath. Lower the rod if you can. If it is a fixed rail, you need a longer curtain; there is no fix for a two-inch gap at the bottom of a shower.
• Too narrow, gaps at the ends. Add a second overlapping liner, or replace it with one that is 1.5 times the rail width. Curtain clips that pull the edge to the wall help with spray but not with the gap itself.

One cheap accessory worth knowing about: a curved shower rod. It adds several inches of elbow room inside a standard tub for about twenty dollars, mounts on tension in many cases, and needs a 72-inch curtain rather than anything special.