function calculateFERS() {
var highThree = parseFloat(document.getElementById("highThree").value);
var serviceYears = parseFloat(document.getElementById("serviceYears").value);
var retireAge = parseInt(document.getElementById("retireAge").value);
var resultBox = document.getElementById("fers-result-box");
if (isNaN(highThree) || isNaN(serviceYears) || isNaN(retireAge)) {
alert("Please enter valid numbers in all fields.");
return;
}
var multiplier = 0.01; // Standard 1%
// FERS Logic: 1.1% multiplier if age is 62 or older AND service is 20 years or more
if (retireAge >= 62 && serviceYears >= 20) {
multiplier = 0.011;
}
var annualAnnuity = highThree * serviceYears * multiplier;
var monthlyAnnuity = annualAnnuity / 12;
document.getElementById("resMultiplier").innerText = (multiplier * 100).toFixed(1) + "%";
document.getElementById("resAnnual").innerText = "$" + annualAnnuity.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resMonthly").innerText = "$" + monthlyAnnuity.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
resultBox.style.display = "block";
}
Understanding Your FERS Benefit Calculation
The Federal Employees Retirement System (FERS) provides a defined benefit pension for federal employees. Unlike private sector 401(k) plans, the FERS annuity is a guaranteed monthly payment based on your salary history and length of service. Understanding how these variables interact is essential for federal retirement planning.
The Three Core Components of FERS
To calculate your gross monthly benefit, you need to identify three specific pieces of data:
High-3 Average Salary: This is the highest average basic pay you earned during any three consecutive years of service. This usually occurs during the final three years of a federal career.
Years of Creditable Service: This includes the total number of years and months you worked for the federal government. Unused sick leave may also be added to this total to increase your benefit.
The Multiplier: This is a percentage determined by your age and years of service at the time of retirement.
How the Multiplier Works
Most FERS employees receive a 1% multiplier. However, there is a significant incentive for staying in the workforce longer. If you retire at age 62 or older with at least 20 years of service, your multiplier increases to 1.1%. This 10% boost in your pension can significantly impact your long-term financial security.
FERS Calculation Example
Consider an employee with the following profile:
High-3 Salary: $100,000
Years of Service: 25 years
Retirement Age: 63
Because the employee is over age 62 and has more than 20 years of service, they qualify for the 1.1% multiplier. The math would be: $100,000 x 25 x 0.011 = $27,500 per year. This results in a gross monthly payment of approximately $2,291.67 before deductions for taxes, insurance, or survivor benefits.
Important Considerations
Note that the figure generated by a FERS benefit calculator is the "Gross" annuity. Your actual take-home pay will be lower after accounting for federal and state income taxes, Federal Employees Health Benefits (FEHB) premiums, Federal Employees' Group Life Insurance (FEGLI), and any survivor benefit elections you choose for your spouse.