Short answer: once a week for a household bathroom, twice a week if three or more people share it. But "clean the bathroom" is really six separate tasks on four different schedules, and treating it as one job is why bathrooms drift.
By task
| Task | How often | Why |
|---|---|---|
| Toilet bowl, seat, base | Weekly | Below weekly, staining sets |
| Basin and taps | Weekly | Toothpaste hardens fast |
| Shower walls and floor | Weekly | Soap scum bonds if left |
| Mirrors | Weekly | Cosmetic, but noticed |
| Floor mopped | Weekly | Around the toilet especially |
| Shower screen descaled | Fortnightly | Limescale is much harder once set |
| Extractor fan cover | Monthly | Dust chokes airflow, then mould follows |
| Grout scrubbed | Monthly–quarterly | Depends on ventilation |
| Plughole cleared | Monthly | Before it becomes a problem |
| Behind and under the toilet | Monthly | The most-skipped spot in the house |
| Shower curtain washed | Monthly | Machine-washable, most are |
The three most-skipped jobs
The extractor fan cover. It clogs with dust, airflow drops, moisture stops leaving the room, and then you have a mould problem you will blame on the building. Most covers unclip and go under a tap. Monthly.
Behind and under the toilet. Not pleasant, genuinely necessary, and the source of most persistent bathroom smell. If a bathroom smells despite looking clean, it is almost always here.
The shower screen bottom track. Water sits in it permanently. It is where scale and mould start, and it is invisible unless you crouch.
The thing that matters more than frequency
Ventilation beats cleaning. A bathroom that dries out after every shower stays clean for far longer than one cleaned twice as often but left damp.
Run the fan during the shower and for fifteen to twenty minutes after, that second part is the bit everyone skips and it does most of the work. Open a window if you have one. Squeegee the screen, which takes ten seconds and roughly halves how often it needs descaling.
If you are paying someone
A standard clean should cover the weekly list above every visit. The fortnightly and monthly tasks should be either scheduled explicitly or listed as deep-clean scope, see deep cleaning vs regular cleaning.
If your cleaner comes fortnightly, that means the weekly-frequency tasks are being done at half the rate they need. That is fine for two people; it shows in a household of five. Match the frequency to the household, not the budget, or you will end up paying for cleaning that never quite gets on top of it.