Splitting rent when a roommate moves out mid-lease
Pro-rate by day, decide who carries the vacant nights, and recalculate everyone’s share from the day the replacement arrives.
In this guide
When a roommate leaves mid-lease, pro-rate their final month by day — their share of the room’s rent × days occupied ÷ days in the month — and settle every shared bill on the existing percentages up to their last day. The vacant days between tenants are the remaining housemates’ cost, split in the same proportion as their own rent, unless the departing roommate agreed in writing to cover the gap. From the replacement’s first day, everyone’s share is recalculated on the current room allocation.
- Pro-rate by day, never by half-month. A 12-day stay in a 30-day month is 40% of the room’s rent, not 50%.
- The three pieces — departing days, vacant days, replacement days — must add back to the room’s full monthly rent exactly.
- Vacant days belong to whoever is still living there, unless the lease or a written house agreement says otherwise.
- Settle utilities on the departure date using the old percentages, then start a new period. Do not carry a mixed month forward.
- The deposit is a separate transaction from rent, and it is between the incoming and outgoing tenants — not the landlord — unless the landlord agrees to re-paper it.
A mid-lease departure is one of the few moments in shared housing where the arithmetic genuinely is the hard part. Everyone is agreed on the principle — pay for what you used — but nobody wants to be the one who works out what that means across three overlapping periods, two different rent allocations and a month that does not divide neatly.
Pro-rate the final month by day
Take the departing person’s existing monthly share — whatever the household already agreed, whether that is equal, by room size or by income — and multiply it by their days of occupancy divided by the number of days in that month. Use the actual length of the month; using 30 for a 31-day month quietly overcharges by a day.
| Period | Who pays | Method | Basis |
|---|---|---|---|
| Up to the last night | The departing roommate | Their existing share × days occupied ÷ days in month | Day count |
| Vacant days | The remaining roommates | Room’s share × vacant days ÷ days in month, split in proportion to their own rent | Day count |
| From the replacement’s first night | The replacement | Room’s share × days occupied ÷ days in month | Day count |
| Shared bills to the departure date | Everyone, old percentages | Settle in full on the departure date; start a fresh period after | Meter or date |
| Deposit | Replacement pays the leaver | Direct transfer for their portion, minus any agreed damage | Separate |
If your lease makes the remaining tenants jointly liable for the whole rent — which most joint tenancies do — the vacant days are legally yours regardless of what the leaver promised. Get any gap-covering agreement in writing before they hand back the keys.
A worked example
A three-bedroom flat at $2,400 a month, split by room size: Room A $900, Room B $800, Room C $700. The Room C tenant leaves after the night of the 12th in a 30-day month. The replacement moves in on the 20th, leaving seven vacant nights.
The seven vacant nights cost $163.33 in total, and they are divided between A and B in proportion to their own rent — 900:800 — rather than equally, because that is the same ratio the household already agreed represents the value each person gets from the place. Splitting the gap equally would hand the smaller room a disproportionate share of a cost neither of them chose.
The full sequence, in order
- Fix the departure date in writing. The last night they sleep there, not the day they finish moving boxes. Everything else is calculated from this one number, so it cannot be fuzzy.
- Settle every shared bill up to that date. Take meter readings where you can, pro-rate flat-rate services like internet by day, and close out the period on the existing percentages. Do not let a mixed month roll into the next one.
- Pro-rate their final rent. Their monthly share × days occupied ÷ days in the month. Round to the cent and let one person absorb any leftover.
- Agree who carries the vacant nights. Default is the remaining housemates, in proportion to their own rent. If the leaver agreed to cover the gap, that agreement needs to exist in writing before they leave, not after.
- Settle the deposit between tenants. The replacement pays the leaver directly for their portion of the deposit, less anything the household has agreed is genuinely their damage. Photograph the room on the day either way.
- Recalculate everyone’s share from day one of the new arrangement. If anyone swaps rooms, the allocation changes for everyone. Write the new numbers down and confirm them before the replacement pays anything.
The cases people get wrong
- Someone swaps into the vacated room. Two shares change, not one. Recalculate the whole allocation rather than patching a single number, or the shares will stop adding up to the rent within two months.
- The replacement arrives before the leaver’s notice ends. Nobody pays twice for the same night. The overlap is the leaver’s cost if they are still keeping the room, and the replacement’s if they are not.
- The leaver stops paying but leaves belongings. Storage is not tenancy. Agree a removal date in writing; belongings in a room do not entitle anyone to occupy it rent-free.
- No replacement is found. The room’s rent falls on the remaining tenants indefinitely under a joint tenancy. Decide early whether you are absorbing it in proportion or renegotiating room allocations, because three months of silent absorption is how households break up.
- A roommate is behind when they leave. Settle it before the keys go back. Chasing a former housemate is far harder than chasing a current one.
Every number in a mid-lease handover is a day count. If it will not reduce to days, it is a negotiation, not a calculation.
Keeping a record that survives the handover
The reason mid-lease departures get contentious months later is that the record leaves with the person. Keep the shared expense history in one place the whole household can see, settle the leaver’s balance to zero on their last day, and start the new period cleanly. A departing housemate whose balance reads zero has nothing to argue about, and neither do you.
Frequently asked questions
How do you pro-rate rent when a roommate moves out?
Who pays the rent for days the room is empty?
How much notice should a roommate give before moving out?
Does the departing roommate get their deposit back from the landlord?
What if the replacement wants a different rent split?
Priya R.
Editorial lead for Expenso’s shared-housing guides
Priya leads Expenso’s editorial work on rent splitting, shared bills and household agreements. Her guides turn common shared-money decisions into methods readers can check and reproduce.
