Answer: More often.
The sad truth is we’re not changing our towels as often as we should be. I know, I know, laundry and physical labour aside it’s just easier to leave them that extra couple of days. Not to mention the water and energy you’re saving not washing your towels and they’ll last longer and the environment! Save it. Change your towels.
I doubt anyone could be blamed for thinking once a week is enough, once every two weeks gets you a warning card any longer and your Royal Splendour will have more culture than you do.
Believe it or not you should be washing and changing your bath towels after every 3-4 uses. Uses and not days as some people shower more than once a day, whereas others may not bathe every day. As a 2x shower a day person it does seem vaguely excessive, though the explanation for the vigorous towel changing lies with where and how you use the towel.
How many uses you get out of a towel depend on how damp the towel gets. Hand towels are getting less wet after each use than a bath towel for example. Not letting the towel dry completely before each use means that you’re potentially putting bacteria back on to your skin and your towel, which of course you don’t want to be doing more than 3 or 4 times.
How to not spend the rest of your natural life laundering towels? Have two going at once, that means you’ve got 6 uses instead of 3, plus we’ll say a grace period of 1.5 uses between the two. That’s 7.5. Practically a week...ish.
A good rule of thumb to rely on if you’re feeling somewhat anti-Towel-Timetable, if it is damp when you pick it up to use it, go get another one. If it smells mildew-y, go get another one. If you’re tired of the colour palette of your Majolica Blue on off-white, marble finish tiles and need a changeup – go get another one. (Artesian Blue will bring you into the warmer months with a soft tropical tone, and is definitely the kind of change up that will make enough of a statement that your happy about the colour, but not enough that you’re thinking “wow has it been 3 uses yet, this colour is using me”.)