FERS Annuity Calculator
Use this calculator to estimate your Federal Employees Retirement System (FERS) basic annuity based on your High-3 average salary, length of service, and age at retirement.
The highest average basic pay you earned during any 3 consecutive years of service.
Used to determine if the 1.1% multiplier applies (requires age 62+ and 20+ years).
Understanding the FERS Annuity Calculation
The FERS basic annuity is a defined benefit pension for federal employees. Unlike Social Security or the TSP, this is a guaranteed monthly payment based on your work history. The formula relies on three primary variables:
- High-3 Salary: This is the average of your highest basic pay over 36 consecutive months. This usually occurs at the end of a career but can be any period where pay was highest.
- Years of Creditable Service: This includes your years and months of actual federal service plus any unused sick leave converted to service time.
- The Multiplier: Most employees receive a 1% multiplier. However, if you retire at age 62 or older with at least 20 years of service, your multiplier increases to 1.1% for your entire career.
The FERS Formula
Basic Formula:
High-3 Average Salary × Years of Service × Multiplier (1.0% or 1.1%) = Annual Annuity
High-3 Average Salary × Years of Service × Multiplier (1.0% or 1.1%) = Annual Annuity
Realistic Calculation Example
Let's look at a federal employee retiring with the following profile:
| High-3 Salary: | $100,000 |
| Service Length: | 30 Years |
| Retirement Age: | 62 |
Because this employee is 62 and has at least 20 years of service, they qualify for the 1.1% multiplier.
$100,000 × 30 years × 0.011 = $33,000 per year ($2,750 per month).
function calculateFERSAnnuity() { var salary = parseFloat(document.getElementById('high3Salary').value); var years = parseFloat(document.getElementById('yearsService').value); var months = parseFloat(document.getElementById('monthsService').value); var age = parseFloat(document.getElementById('retirementAge').value); var resultDiv = document.getElementById('fersResult'); if (isNaN(salary) || isNaN(years) || isNaN(months) || isNaN(age)) { resultDiv.style.display = 'block'; resultDiv.innerHTML = 'Please enter valid numeric values for all fields.'; return; } // Convert months to decimal years var totalYears = years + (months / 12); // Determine Multiplier var multiplier = 0.01; var isEnhanced = false; if (age >= 62 && totalYears >= 20) { multiplier = 0.011; isEnhanced = true; } // Calculations var annualAnnuity = salary * totalYears * multiplier; var monthlyAnnuity = annualAnnuity / 12; // Formatting var formatter = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD', }); resultDiv.style.display = 'block'; resultDiv.innerHTML = 'Calculation Results
' + 'Total Service Credit: ' + totalYears.toFixed(2) + ' years' + 'Applicable Multiplier: ' + (multiplier * 100).toFixed(1) + '%' + (isEnhanced ? ' (Enhanced Rate Applied)' : ") + " + '' + 'Estimated Annual Annuity: ' + formatter.format(annualAnnuity) + '' + 'Estimated Monthly Payment: ' + formatter.format(monthlyAnnuity) + '' + '*This is a gross estimate. It does not account for survivor benefit elections, FEHB premiums, taxes, or the FERS Special Retirement Supplement.'; }