When pro rata rent applies
Tenancies rarely start on the first of a month and end on the last day of one. When you move in or out mid-month, somebody has to turn a monthly rent into a charge for part of a month — and that is a pro rata rent calculation. It appears at the start of a tenancy (the first payment is often a part-month plus the first full month), at the end when a fixed term or a notice period finishes mid-month, and whenever a rent change takes effect part-way through a rental period.
The idea is the same as pro rata salary: a full amount, scaled by the fraction of the period it covers. What surprises tenants is that there are two standard ways of working out the daily rate, they give slightly different answers, and tenancy agreements almost never say which one will be used.
The two methods, and why they differ
The annual method spreads the year's rent evenly over the year: monthly rent × 12 ÷ 365 gives a daily rate that is the same in every month. It is simple, consistent, and easy to check — £1,200 a month becomes £39.45 a day in February and £39.45 a day in July.
The calendar-month method divides the rent by the days in the actual month: £1,200 ÷ 30 in April gives £40.00 a day, but £1,200 ÷ 31 in May gives £38.71 a day. Under this method the same number of days costs more in a short month than in a long one — the opposite quirk to the annual method, under which a day in February “uses up” more of that month's rent.
Neither method is the legally correct one; both are in everyday use by landlords, letting agents and housing associations, and the difference on a typical move is a few pounds. The calculator above always shows both, so if an agent's figure differs from yours you can see immediately which daily rate they used. If you are working from dates for a period that is not rent — a salary part-period, a subscription, a premium — the pro rata date calculator covers the same ground with a choice of day-count methods.
Worked example
A tenancy at £1,200 a month starts on 20 April. April has 30 days, and counting both the first and the last day, 20 to 30 April is 11 days. The annual method gives £1,200 × 12 ÷ 365 = £39.45 a day, so 11 days is £433.97. The calendar-month method gives £1,200 ÷ 30 = £40.00 a day, so 11 days is £440.00. The two methods differ by £6.03 — worth knowing about, not worth falling out over.
The same tenancy, priced for 10 days in a 31-day month, shows the gap the other way: annual method £394.52, calendar-month method £387.10. Over a full month both methods agree exactly — you owe the whole month's rent — which is a useful check on any part-month figure you are quoted.
Deposits and first payments
Deposits are not pro rated, and in England they are capped by the Tenant Fees Act 2019. This is general information, not legal advice, and the rules differ in Scotland, Wales and Northern Ireland.
- Tenancy deposit: capped at 5 weeks' rent where the annual rent is under £50,000, and 6 weeks' rent where it is £50,000 or more. On £1,200 a month (£276.92 a week) the cap is £1,384.62.
- Holding deposit: capped at 1 week's rent (£276.92 on the same tenancy), and it must be refunded or put towards the first rent or deposit when the tenancy goes ahead.
A typical first payment is therefore: the pro rata rent from your move-in date to the end of that month, plus the first full month, plus the deposit — which is why the pro rata figure matters: it is the one part of the first payment that depends on a calculation you can check. For part-period amounts of any kind, see the pro rata date calculator; for part-time pay, the main pro rata calculator.
Frequently asked questions
Two methods are in common use. The annual method turns the monthly rent into a daily rate across the whole year: monthly rent × 12 ÷ 365, multiplied by the days you are there. The calendar-month method divides the rent by the days in that particular month: rent ÷ days in the month × days. On £1,200 a month for 10 days, the annual method gives £394.52 and the calendar-month method in a 31-day month gives £387.10.
You normally owe rent up to the end of your tenancy or notice period, worked out pro rata to that date if it falls mid-month — not to the day you hand back the keys, unless your landlord re-lets the property or agrees a surrender. If the property is re-let before your liability ends, you should not be charged twice for the same days. Check your tenancy agreement and keep any agreement to end early in writing.
For the part-month at the start or end of a tenancy, no — rent for a partial period is the proportion of the monthly rent for the days covered, which is what this calculator works out. During the tenancy itself, rent is usually paid in full monthly instalments in advance, even in the final month if the tenancy ends mid-month, with the excess refunded or the last payment adjusted. If a full month has been taken for a part-month with no adjustment, ask for the calculation in writing.
Both are in everyday use, and tenancy agreements rarely say which. Letting agents' software commonly uses the calendar-month method; many landlords and housing associations use the annual method because the daily rate stays the same all year. The difference on a typical move is a few pounds — if your figure and theirs differ, ask which daily rate they used.
No. Your tenancy deposit is a separate amount, capped by law, and is not pro rated. In England the cap is five weeks' rent where the annual rent is under £50,000. Pro rata applies to rent for part-periods, not to the deposit.