Prorated Rent Calculator
Calculate a partial month's rent when a tenancy starts or ends mid-month.
What this calculator does
This calculator works out the part-month rent due when a tenancy starts or ends partway through a rental period. Enter the monthly rent, the number of days in the month, and the days occupied, and it returns the daily rate and the amount payable.
The formula is monthly rent divided by days in the month, multiplied by days occupied. It is straightforward arithmetic, but worth setting out explicitly because both figures — the daily rate and the total — belong in the tenancy agreement and on the first rent demand. A part-month charge that arrives without an explanation is one of the more common early causes of friction between landlord and tenant.
When to use it
The standard case is a tenancy starting mid-month where rent is then collected on a fixed date, typically the 1st. It applies equally when a joint tenant is added or replaced partway through a period, and when a periodic tenancy ends on a date that does not align with the rental cycle.
Landlords and agents also use it when implementing a rent increase that takes effect mid-period, charging the old rate for its days and the new rate for the remainder. And it resolves queries quickly: a tenant who questions the first payment is almost always satisfied by seeing the daily rate and the day count set out, which is far cheaper than a dispute reaching a redress scheme.
Understanding the inputs
Monthly rent is the full contractual rent before any incentive. If a rent-free period or move-in discount applies, show it as a separate line rather than reducing the rent figure, so the agreement and the invoice stay consistent with each other.
Days in month sets the method. Entering the actual calendar days — 28, 29, 30, or 31 — gives the calendar-month approach. Many UK agents instead use the annual method, multiplying monthly rent by twelve and dividing by 365, which produces a constant daily rate all year; to replicate it, work out that daily figure separately and compare. Days occupied should include the first day of the tenancy.
How is this calculated?
Prorated Rent = (Monthly Rent / Days in Month) × Days Occupied
A worked example
A tenancy starts on 18 September with rent of £1,250 a month. September has 30 days, so the tenant occupies 13 days from the 18th to the 30th inclusive. The daily rate is £1,250 divided by 30, or £41.67, giving part-month rent of £541.67.
Under the annual method the figures differ slightly. Annual rent of £15,000 divided by 365 gives £41.10 a day, and 13 days comes to £534.25 — about £7 less. Neither is wrong, but the agreement should say which applies. Note too that the deposit is unaffected: with annual rent under £50,000 the cap is five weeks' rent, calculated on the full £1,250 monthly figure and giving £1,442, payable in full and protected in an approved scheme within 30 days.
Limitations and assumptions
The calculator does the arithmetic; it cannot interpret your agreement. Whether the calendar-month or annual method applies, whether the first day counts, and when the part-month payment falls due are all matters for the tenancy agreement, and they should be stated there rather than assumed.
It covers rent only. Deposits are never prorated and are capped at five or six weeks' rent under the Tenant Fees Act, and permitted payments are tightly restricted — most administration and referencing fees are prohibited outright. Fixed monthly charges such as parking or a furniture package should be prorated on the same day count, while metered utilities and council tax run from the tenancy start date and are handled separately by the supplier and the council.
Common Questions
- Which method do UK letting agents use?
- Most commonly the annual method: monthly rent times twelve, divided by 365, times the days occupied. On £1,250 a month that gives a daily rate of £41.10. The alternative is dividing by the actual days in the month, which gives £41.67 in a 30-day month. Agree which applies before signing.
- Does the tenancy start date count as a day?
- Yes. Rent is normally charged from and including the first day of the tenancy, so a start date of the 18th in a 30-day month means 13 days through to the 30th. Because a single day is real money, the tenancy agreement should state the period and the amount explicitly.
- Is prorated rent required by law?
- There is no statutory requirement, but charging a full month for a few days would almost certainly be an unfair term under the Consumer Rights Act 2015 and would be hard to enforce. In practice, every reputable agent and landlord prorates, and the Tenant Fees Act 2019 restricts what else can be charged.
- When is the part-month payment due?
- Usually before or on the day the tenancy starts, alongside the deposit and the first full month. Some agents instead add it to the second month's payment to reduce the amount needed at move-in. Either is acceptable provided the agreement is clear about the amount and the date.
- How does this interact with the deposit cap?
- The Tenant Fees Act caps deposits at five weeks' rent where annual rent is under £50,000, and six weeks above that. The cap is calculated on the full monthly rent, not the prorated amount, and deposits are never prorated. The deposit must also be protected in an approved scheme within 30 days.
- Does proration apply at the end of a tenancy?
- It depends on how the tenancy ends. A fixed term ending mid-month, or a periodic tenancy ended by a valid notice expiring mid-period, can produce a part-month charge. Where a tenant serves notice under a periodic tenancy, the notice must usually expire at the end of a rental period, which often removes the question.
- How do I prorate a rent increase?
- Run the calculation twice — old rate for the days before the increase, new rate for the days after — and show both lines. Increases during a fixed term generally require a clause permitting it or the tenant's agreement; otherwise a section 13 notice applies to periodic tenancies, with at least one month's notice.
- Should service charges or bills be prorated too?
- Anything charged as a fixed monthly amount for the period occupied normally should be, on the same day count as the rent. Utilities billed on meter readings are handled by the supplier from the tenancy start date instead. Council tax liability also starts on the day the tenancy begins, not the first of the month.
- What if the landlord refuses to prorate?
- Ask for the calculation in writing and query it against the tenancy agreement. A term requiring a full month's rent for a few days' occupancy is likely unenforceable as an unfair term. If an agent insists, raise it with their redress scheme, membership of which is mandatory for letting agents.
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