Usually the day before your next full rent payment is due.
Standard Annualised (Rent × 12 ÷ 365)
Days in Month (Rent ÷ Days in Month)
Most UK agencies use the Standard Annualised method.
Please enter valid rental amounts and dates. End date must be after start date.
Number of Days:0
Daily Rate:£0.00
Total Pro Rata Payment:£0.00
Understanding Pro Rata Rent in the UK
When you move into a rental property partway through a month, you are typically not required to pay the full month's rent immediately. Instead, landlords and letting agencies in the UK calculate a "pro rata" payment. This ensures you only pay for the exact number of days you occupy the property before the first full billing cycle begins.
How is Pro Rata Rent Calculated?
There is no single statutory formula for calculating pro rata rent in UK law, but two main methods are commonly used by letting agents and landlords. It is crucial to check your tenancy agreement to see which method applies to you.
Method 1: The Annualised Method (Standard)
This is the most common and generally considered the fairest method, as it equalises the cost across the year regardless of whether a month has 28, 30, or 31 days.
(Monthly Rent × 12) ÷ 365 = Daily Rate
Daily Rate × Number of Days = Pro Rata Rent
Note: In a leap year, some agencies divide by 366.
Method 2: The Actual Days Method
This method calculates the daily rate based on the specific month you are moving in. While simpler, it can lead to slight fluctuations in daily costs depending on the month.
Monthly Rent ÷ Total Days in Current Month = Daily Rate
Daily Rate × Number of Days = Pro Rata Rent
Example Scenario
Imagine your monthly rent is £1,200. You move in on the 20th of September, and your regular rent payment date is set for the 1st of every month. You need to pay for the period from September 20th to September 30th.
Days covered: 20th to 30th inclusive = 11 days.
Using Annualised Method: (£1,200 × 12) ÷ 365 = £39.45 daily rate. £39.45 × 11 days = £433.97.
Using Monthly Method: £1,200 ÷ 30 (days in Sept) = £40.00 daily rate. £40.00 × 11 days = £440.00.
When Do I Pay Pro Rata Rent?
Typically, the pro rata amount is paid before you receive the keys. It is often bundled with your tenancy deposit and occasionally the first full month's rent, depending on the agency's policy. Always ask for a breakdown of the initial invoice to ensure the maths matches the agreed formula.
function calculateRent() {
// 1. Get DOM elements
var rentInput = document.getElementById('monthlyRent');
var startInput = document.getElementById('startDate');
var endInput = document.getElementById('endDate');
var methodInput = document.getElementById('calcMethod');
var errorMsg = document.getElementById('errorMsg');
var resultBox = document.getElementById('resultBox');
var resDays = document.getElementById('resDays');
var resDailyRate = document.getElementById('resDailyRate');
var resTotal = document.getElementById('resTotal');
// 2. Parse Values
var rent = parseFloat(rentInput.value);
var startStr = startInput.value;
var endStr = endInput.value;
var method = methodInput.value;
// 3. Reset State
errorMsg.style.display = 'none';
resultBox.style.display = 'none';
// 4. Validation
if (isNaN(rent) || rent < 0 || !startStr || !endStr) {
errorMsg.innerText = "Please enter a valid rental amount and select both dates.";
errorMsg.style.display = 'block';
return;
}
var startDate = new Date(startStr);
var endDate = new Date(endStr);
// Reset hours to ensure day difference calculation works purely on calendar dates
startDate.setHours(0, 0, 0, 0);
endDate.setHours(0, 0, 0, 0);
if (endDate < startDate) {
errorMsg.innerText = "The Period End Date cannot be before the Start Date.";
errorMsg.style.display = 'block';
return;
}
// 5. Calculate Number of Days (Inclusive)
// Difference in milliseconds divided by ms per day
var diffTime = Math.abs(endDate – startDate);
var diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24)) + 1;
// 6. Calculate Daily Rate
var dailyRate = 0;
if (method === 'annual') {
// Standard UK Agency Formula: (Rent * 12) / 365
dailyRate = (rent * 12) / 365;
} else {
// Monthly Method: Rent / Days in that specific month
// We use the month of the start date for the divisor
var year = startDate.getFullYear();
var month = startDate.getMonth() + 1; // 1-12
var daysInMonth = new Date(year, month, 0).getDate();
dailyRate = rent / daysInMonth;
}
// 7. Calculate Total
var totalProRata = dailyRate * diffDays;
// 8. Output Results
resDays.innerText = diffDays;
resDailyRate.innerText = "£" + dailyRate.toFixed(2);
resTotal.innerText = "£" + totalProRata.toFixed(2);
resultBox.style.display = 'block';
}