Two limits, not one
A guest rule needs two numbers. Nights in a row stops the visit that never ends. Total nights in a window stops the guest who goes home on Sunday and is back on Friday.
A lease with only the first number is passed by every weekend guest without ever being broken. A lease with only the second lets someone stay a full week straight. Write both, and say who can approve more.
- Nights in a row: 3 is common in a shared house, 7 in a home rented whole
- Total nights: 4 in any 30 days is one weekend in two
- Who approves more: you, in writing, before the stay
Any 30 days is not a calendar month
Counted by the calendar month, a guest can stay the last four nights of September and the first four of October and pass no limit of four. That is eight nights in eight days.
So the count here moves with the guest. For each night, it looks back over the 30 days that end on that night. The first night that makes five is the night the limit was passed.
What to do the week it is passed
Write to the resident that week, with the dates. A note that lists the nights is hard to argue with. One that says your guest is here all the time is not.
Give two ways forward. The stays come back inside the limit, or the guest applies to be added to the lease and is screened like anyone else. Either one is a fine outcome for the house.
Do not wait a few months to see how it goes. State law decides when a long-staying guest gains the rights of a tenant, and it differs from state to state. The first week is the cheap time to act.
A worked example
A shared house. The lease allows a guest 3 nights in a row and 4 nights in any 30 days. One resident has a guest stay Friday and Saturday night, three weekends running, starting Friday 09/04/2026.
- Nights in a row the lease allows
- 3
- Nights in any 30 days the lease allows
- 4
- Nights stayed
- 6
- Longest stay in a row
- 2 nights
- Most nights in any 30 days
- 6 nights
No single visit broke the rule. The fifth night did, on the third Friday. That is why the lease needs the second number.
Common questions
How many nights can a guest stay before they count as living there?
Your lease sets the house's limit, and your state's law decides when a guest gains a tenant's rights. For the lease, state two numbers: nights in a row, and total nights in any 30 days. Many shared houses use 3 and 4. For the law, read your state's rule or ask a local attorney, because it differs from state to state.
What counts as a night?
A night the guest slept at the house. Name it by the date the evening began: the night of 09/04/2026 runs into the morning of 09/05/2026. An afternoon visit is not a night.
How do I know which nights a guest stayed?
From the notice your lease asks for. A good guest clause has the resident tell the house before an overnight guest. Housemates will also tell you, with dates, if you ask them to. Use the nights you can stand behind, and invite the resident to correct the count.
Can I charge a fee when the limit is passed?
Only if your lease says so, and only the amount it says. If the lease is silent, write to the resident first and add a guest clause with both limits at the next renewal.
These calculators are educational and are not legal, tax, lending, or accounting advice. Rules vary by state and by city, and your lease governs your own properties. Check your own requirements before relying on any number here.