Calculate per-diem costs and prorated rent amounts
30 Days (Standard/April/June/Sept/Nov)
31 Days (Jan/Mar/May/July/Aug/Oct/Dec)
28 Days (February Non-Leap)
29 Days (February Leap Year)
30.42 Days (Yearly Average)
Enter the number of days the tenant will pay for (e.g., moving in on the 15th).
Please enter a valid rent amount.
Daily Rent Rate:$0.00
Days Charged:0
Total Prorated Rent:$0.00
function calculateRent() {
// 1. Get input values using exact IDs
var rentInput = document.getElementById("rentAmount").value;
var monthDaysInput = document.getElementById("daysInMonth").value;
var occupiedInput = document.getElementById("occupiedDays").value;
var errorDiv = document.getElementById("errorMsg");
var resultsDiv = document.getElementById("results");
// 2. Validate inputs
if (rentInput === "" || parseFloat(rentInput) < 0) {
errorDiv.style.display = "block";
resultsDiv.style.display = "none";
return;
} else {
errorDiv.style.display = "none";
}
// 3. Parse numbers safely
var monthlyRent = parseFloat(rentInput);
var daysInMonth = parseFloat(monthDaysInput);
var daysOccupied = occupiedInput === "" ? 0 : parseFloat(occupiedInput);
// 4. Calculate Daily Rate
// Logic: Daily Rate = Monthly Rent / Days in that specific month
var dailyRate = monthlyRent / daysInMonth;
// 5. Calculate Prorated Total
// Logic: Total = Daily Rate * Days Occupied
// If days occupied is 0 or empty, we assume they just want the daily rate,
// but for the total output, we will show 0 if input is empty, or full month if they entered full days.
// Let's stick to strict multiplication.
var totalProrated = dailyRate * daysOccupied;
// 6. Update HTML Results
document.getElementById("dailyRateResult").innerHTML = "$" + dailyRate.toFixed(2);
document.getElementById("daysCountResult").innerHTML = daysOccupied;
document.getElementById("totalProratedResult").innerHTML = "$" + totalProrated.toFixed(2);
// 7. Show results container
resultsDiv.style.display = "block";
}
Understanding the Daily Rent Rate Calculator
Whether you are a landlord managing multiple properties or a tenant moving mid-month, determining the exact daily cost of rent is crucial for accurate billing. The Daily Rent Rate Calculator helps you break down a monthly lease payment into a per-diem amount, allowing for precise proration.
Why Calculate Daily Rent?
Calculating the daily rent rate is most commonly required for prorated rent. Proration occurs when a tenant does not occupy a property for the entire billing cycle (usually a month). Common scenarios include:
Moving In: A tenant moves in on the 10th of the month, requiring payment for only the remaining 20 or 21 days.
Moving Out: A tenant leaves before the lease end date or mid-month, requiring a refund or a partial payment.
Short-Term Extensions: A tenant needs to stay a few extra days past their lease expiration.
The Formula: How to Calculate Daily Rent
The math behind calculating daily rent depends on the method chosen by the landlord or specified in the lease agreement. There are three primary methods used in real estate:
1. Actual Days Method (Most Common) Formula: Monthly Rent ÷ Number of Days in the Current Month
In this method, the daily rate changes depending on whether the month has 28, 30, or 31 days. This is generally considered the most fair method for short-term proration.
2. The 30-Day Banker's Month Formula: Monthly Rent ÷ 30
Some leases stipulate that every month is treated as a 30-day month, regardless of the calendar. This standardizes the daily rate throughout the year but can lead to slight discrepancies in months with 31 days or February.
This calculates the daily rate based on the annualized cost of the rent. This results in a consistent daily rate across the entire year (approximately Monthly Rent ÷ 30.42).
Example Calculation
Let's assume a tenant signs a lease for an apartment with a monthly rent of $1,800 and moves in on September 15th.
September has 30 days.
Step 1: Determine Daily Rate
$1,800 ÷ 30 days = $60.00 per day
Step 2: Count Billable Days
From September 15th to September 30th (inclusive) is 16 days.
If the same tenant moved in on October 15th (October has 31 days):
Daily Rate: $1,800 ÷ 31 = $58.06
Billable Days: 17 days (15th to 31st)
Total: $58.06 × 17 = $987.02
Tips for Landlords and Tenants
Always check your lease agreement before calculating proration. Some states have specific laws regarding how proration must be handled, while others leave it to the lease terms. Using the "Actual Days" method is usually the safest bet to avoid disputes, as it reflects the reality of the calendar.