Pro Rata Rent Calculator UK

What is pro rata rent and when does it apply?

Pro rata rent is a proportional charge for the days a tenant occupies a property during a partial rental period, rather than paying a full month's rent. It arises most commonly when a tenancy begins or ends mid-month, for example, when a tenant moves in on the 15th rather than the 1st, or gives notice partway through a rent period.

Landlords use pro rata rent to ensure the first and last payments reflect actual occupation rather than charging for days the property was empty. It also applies when a tenancy due date changes, such as when a tenant switches from a weekly to a monthly payment schedule. The calculator below handles all of these scenarios.

Ready to try August?

What this pro rata rent calculator does

Most tools give one number. Ours shows the amount and the method behind it, so everyone can see the working:

• Choose Monthly / Weekly / Four-weekly rent schedules.

• Pick a calculation method (see below) and we show the daily rate used.

• Handle move-in or move-out pro-rations, including rent-due-date alignment.

• Generate a clean breakdown for the tenancy file and export it to August in one click.

How to calculate pro rata rent: two UK methods

Both approaches are used in UK lettings. The key is to pick one method and apply it consistently, preferably as stated in your tenancy agreement.

1. “Exact Month” method (calendar-accurate)
   Daily rate = Monthly rent ÷ number of days in that calendar month
   Pro-rata amount = Daily rate × number of occupied days

• Pros: Mirrors the actual month length (28–31 days).

• Cons: The daily rate changes each month.

• Typical for: Managing agents and most ASTs that reference calendar months.

2. “365-day” method (annualised)
   Daily rate = (Monthly rent × 12) ÷ 365 (use 366 in a leap year if you want strict accuracy)
   Pro-rata amount = Daily rate × number of occupied days

• Pros: One unchanging daily rate (transparent across months).

• Cons: Slightly different to the Days-in-Month figure in 28/29/31-day months.

• Typical for: Portfolio reporting and lenders’ pro-rations.

Which should I use?
If your AST specifies a method, use that. If not, the Exact Month method is the most intuitive for tenants. The 365-day method is best for portfolio consistency. The calculator supports both and shows the difference.

Worked examples: exact month and 365-day calculations

Example A — Move-in mid-month (Exact Month)

• Monthly rent: £1,500 (due on the 1st of each month)

• Tenancy start: 15 September 2025 (30-day month)

• Occupied days in Sept: 16 (15th–30th inclusive)

• Daily rate: £1,500 ÷ 30 = £50.00

• Pro-rata due at move-in: 16 × £50.00 = £800.00

• Next full payment: £1,500 on 1 October.

Example B — Move-out part-way (365-day method)

• Monthly rent: £1,200 (due on the 10th)

• Move-out: 28 February 2026 (leap year; choose 366 for strict accuracy)

• Occupied days in final period: 19 (10th–28th inclusive)

• Daily rate: (£1,200 × 12) ÷ 366 = £39.34

• Final pro-rata: 19 × £39.34 ≈ £748.

• If the tenant paid the full £1,200 on 10 Feb, the landlord refunds ≈ £452.

Pro rata rent for weekly and four-weekly tenancies

Some tenancies legitimately use weekly or four-weekly rent (common in HMOs). Use these rules:

• Weekly rent- Daily rate = Weekly rent ÷ 7. Pro-rata = daily rate × occupied days.

• Four-weekly rent - Daily rate = Four-weekly rent ÷ 28.

• If converting weekly to monthly for comparables, use Weekly × 52 ÷ 12 (not 4.33 rounded by hand, use the calculator).

Best practice: writing the method into your tenancy

• Write the method into your tenancy agreement or offer letter (“Pro-rata rent will be calculated using the [Exact Month / 365-day] method”).

• Show your working - Share the breakdown (daily rate × days).

• Keep dates consistent - Count the start and end dates you agree (inclusive), and use the same approach for refunds.

• Separate rent from fees/deposit - Pro-rata rent is rent. Keep deposits, damages, and any permitted fees distinct in the ledger.

How to use the August Pro-Rata Calculator

1. Select rent schedule (Monthly / Weekly / Four-weekly) and enter the headline rent.

2. Choose Move-in or Move-out, add the relevant start/end dates, and (for monthly) select Exact Month or 365-day method.

3. Optional: Align to due date, set rounding.

4. Hit Calculate for the pro-rated amount and the daily-rate working.

Getting partial rent calculations right is especially important at the start of a tenancy. Our guide to how to do a right-to-rent check in 2026 covers the other key step landlords must take before a new tenant moves in, and our article on fixed-term tenancies abolished explains how the shift to periodic tenancies from May 2026 may affect when and how rent periods are structured going forward.

Disclaimer

This calculator provides pro-rata rent payment estimates for guidance only and does not constitute legal, financial, or tenancy advice. Actual amounts payable or refundable may vary depending on your tenancy agreement, landlord policies, and applicable regulations. Always confirm amounts with your landlord, letting agent, or a qualified housing adviser before making payment decisions.