The full bonus amount you would receive if you worked the entire period.
Or end of the bonus period (e.g., Dec 31).
Standard year is 365, Leap year is 366.
Days Worked / Eligible:0
Proration Percentage:0%
Full Target Bonus:$0.00
Pro-Rated Bonus Payable:$0.00
How to Calculate Your Pro-Rated Bonus
A pro-rated bonus is a payment calculated based on the specific portion of a time period (usually a fiscal year) that an employee was actively employed or eligible for the bonus. If you joined a company halfway through the year, or left before the year ended, you likely aren't eligible for the full annual bonus amount, but rather a "pro-rated" portion of it.
The Pro-Rated Bonus Formula
The calculation for a pro-rated bonus is straightforward. It is essentially a ratio of the time you worked compared to the total time in the bonus period.
Formula:
(Days Employed / Total Days in Period) × Full Bonus Amount = Pro-Rated Bonus
Step-by-Step Example
Let's look at a realistic scenario using the logic from the calculator above:
Full Target Bonus: $20,000
Start Date: April 1st
End Date: December 31st (End of Year)
Step 1: Calculate Days Worked.
From April 1st to December 31st is approximately 275 days.
Step 2: Determine Total Period.
A standard non-leap year has 365 days.
While some organizations calculate pro-ration based on full months worked (e.g., 9/12 months), calculating by days is the most accurate method and the standard for legal and accounting precision. Using a daily count accounts for starting in the middle of a month, which a simple monthly division might miss or round incorrectly.
Common Scenarios for Proration
New Hires: Employees who start after the beginning of the fiscal year.
Terminations: Employees who leave the company before the payout date (if the company policy allows for payout upon exit).
Leaves of Absence: In some jurisdictions or company policies, unpaid leaves may be deducted from the "active days" count, reducing the bonus pro-rata.
Part-Time to Full-Time: If you switched status during the year, a weighted average might be used, though this calculator focuses on the duration of employment.
Tax Implications
Remember that your pro-rated bonus is considered supplemental income. In the United States, for example, it is often taxed at a flat supplemental rate (often 22% for federal withholding) which may differ from your regular paycheck withholding. Always consult a tax professional to understand your net take-home pay.
function calculateProratedBonus() {
// 1. Get DOM elements
var fullBonusInput = document.getElementById("fullBonusAmount");
var startDateInput = document.getElementById("startDate");
var endDateInput = document.getElementById("endDate");
var periodDaysInput = document.getElementById("totalPeriodDays");
var resultBox = document.getElementById("result-box");
// 2. Get values
var fullBonus = parseFloat(fullBonusInput.value);
var periodDays = parseFloat(periodDaysInput.value);
var startDateStr = startDateInput.value;
var endDateStr = endDateInput.value;
// 3. Validation
if (isNaN(fullBonus) || fullBonus < 0) {
alert("Please enter a valid Total Target Bonus Amount.");
return;
}
if (!startDateStr || !endDateStr) {
alert("Please select both a Start Date and an End Date.");
return;
}
if (isNaN(periodDays) || periodDays <= 0) {
alert("Please enter a valid number of days for the bonus period (e.g., 365).");
return;
}
// 4. Date Logic
var start = new Date(startDateStr);
var end = new Date(endDateStr);
// Normalize time to midnight to ensure accurate day count
start.setHours(0, 0, 0, 0);
end.setHours(0, 0, 0, 0);
if (end periodDays) {
// We allow it but warn visually, or just calculate as is (some bonuses might be for > 1 year).
// For this specific tool, let's cap percentage at 100% logic unless explicitly desired?
// Actually, let's leave it raw math, but usually it shouldn't exceed 100%.
// We will calculate strict ratio.
}
// 5. Calculation
var ratio = daysWorked / periodDays;
var proratedAmount = fullBonus * ratio;
var percentage = ratio * 100;
// 6. formatting Currency
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
// 7. Display Results
document.getElementById("resDaysWorked").innerHTML = daysWorked + " days";
document.getElementById("resPercentage").innerHTML = percentage.toFixed(2) + "%";
document.getElementById("resFullBonus").innerHTML = formatter.format(fullBonus);
document.getElementById("resFinalBonus").innerHTML = formatter.format(proratedAmount);
// Show result box
resultBox.style.display = "block";
}