The most commonly-available towel bar sizes are 18-inch and 24-inch. However, it's possible to find in-between sizes of 20- or 22-inch, as well as 30- and 36-inch sizes. The smaller towel bars are meant for hand towels, but any towel bar over 22 inches should be sturdy enough to hold bath towels. The correct towel bar size for you depends on your towel sizes and hanging preferences, plus the size of your bathroom.
Towel and Towel Bar Sizes
Most hand towels are 16 inches wide, or 8 inches when folded lengthwise. This allows you to fit two folded hand towels on an 18-inch towel bar, or one unfolded hand towel.
Bath towels average 27 to 30 inches wide, or 13.5 to 15 inches when folded. A 24-inch towel bar will hold one folded bath towel, but the towel will be slightly scrunched when hung unfolded. If the scrunching bothers you and you want to hang your bath towel open and flat, you'll need to use a 30-inch or larger towel bar.
Bath sheets are extra-large towels that measure 35 inches wide, or 17.5 inches when folded. To hang a bath sheet open and flat, you will need a 36-inch towel bar, but a a 24-inch or 30-inch towel bar will hang a folded bath sheet.
For a standard size bathroom that is 5 feet by 8 feet, or smaller, use 18- to 24-inch towel bars to keep the hardware in proportion to the size of the room. If you have a large bathroom with abundant wall space, you have the luxury of using 30- to 36-inch towel bars to create a spacious display for your towels.
Measuring an Existing Towel Bar
When you want to replace an existing towel bar, measure along the bar between the inside edges of the supports. Typically, this measurement will not be an even number of inches, so round up to find the size of replacement you need. For example, if your existing towel bar measures 17.75 inches, you would need an 18-inch towel bar as a replacement. An existing towel bar that measures 23.5 inches between supports would be replaced by a 24-inch towel bar.
Whether you install a new towel bar or replace an existing one, you must make sure the supports are firmly anchored into the wall. Follow the manufacturer's instructions and safety guidelines when using a power drill.