Pro Rate Calculation

Pro-Rate Calculator

Calculate proportional costs for rent, subscriptions, or services.

How many days are being charged for?

Calculation Summary

Daily Rate: $0.00

Prorated Total: $0.00

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Understanding Pro-Rate Calculations

A pro-rate calculation is used to determine the fair cost of a service or rental when it is only used for a portion of a standard billing period. This is most common in real estate (rent), insurance premiums, and subscription-based software services.

The Pro-Rate Formula

To calculate a prorated amount manually, you follow two simple steps:

1. Identify Daily Rate: Total Cost ÷ Total Days in Billing Period
2. Calculate Final Charge: Daily Rate × Number of Days Used

Real-World Example: Rental Proration

Imagine you are moving into a new apartment on the 10th of a 30-day month. Your full monthly rent is $1,800. You only need to pay for the 21 days you will actually be living there (the 10th through the 30th inclusive).

• Daily Rate: $1,800 / 30 = $60.00 per day
• Days Occupied: 21 days
• Total Prorated Rent: $60.00 × 21 = $1,260.00

Common Use Cases

• Mid-month Move-ins: Calculating the first partial month of rent.
• Service Cancellations: Determining the refund amount for a prepaid service.
• Employee Compensation: Calculating pay for a new hire starting in the middle of a pay cycle.
• Utility Adjustments: Allocating costs between outgoing and incoming tenants.

Pro-Rating FAQ

Does the number of days in the month matter?

Yes. Your daily rate will be slightly higher in February (28 days) than in July (31 days). Always use the exact number of days in the specific billing period for accuracy.

Do I count the move-in day?

Standard practice usually includes the day of possession or the start date of the service as the first "used" day.

function calculateProration() { var totalCost = parseFloat(document.getElementById("totalPeriodCost").value); var periodDays = parseFloat(document.getElementById("daysInPeriod").value); var usedDays = parseFloat(document.getElementById("daysUsed").value); var resultContainer = document.getElementById("prorateResultContainer"); var dailyRateDisplay = document.getElementById("dailyRateOutput"); var totalDisplay = document.getElementById("proratedTotalOutput"); if (isNaN(totalCost) || isNaN(periodDays) || isNaN(usedDays) || periodDays periodDays) { alert("Warning: Days used exceeds the total days in the period."); } // Calculation Logic var dailyRate = totalCost / periodDays; var proratedTotal = dailyRate * usedDays; // Display Results dailyRateDisplay.innerText = "$" + dailyRate.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); totalDisplay.innerText = "$" + proratedTotal.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}); resultContainer.style.display = "block"; // Scroll to result for mobile users resultContainer.scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }