Estimates your potential monthly IMRF pension benefit.
Your estimated monthly pension will appear here.
Understanding the IMRF Pension Calculation
The Illinois Municipal Retirement Fund (IMRF) provides retirement annuities to its members. The calculation of your monthly pension benefit is based on a formula that considers your years of credited service and your average final salary. While the exact formulas can be complex and may involve specific plan rules or variations, a common simplified model can illustrate the general principle.
The Core Formula
A simplified approach to estimating your IMRF pension involves multiplying your years of service by your average final salary and then by a pension factor. The result is typically an annual amount that is then divided by 12 to get a monthly estimate.
The formula can be represented as:
Annual Pension = (Years of Service) × (Average Final Salary) × (Pension Factor)
And the monthly pension would be:
Monthly Pension = Annual Pension / 12
Key Components Explained:
Years of Service: This represents the total number of years you have contributed to IMRF. It's important to have accurate records of your service.
Average Final Salary: IMRF typically uses your average earnings over a specific period, most commonly the last four years of your employment. This is your gross salary before taxes.
Pension Factor: This is a percentage multiplier determined by IMRF. For most members who participate in the "Regular" plan, the pension factor is 2.2% (or 0.022) per year of service. For members in the "SLEP" ( salário de emprego público – Public Safety Employee) plan, the factor is typically 3% (or 0.03) per year. This calculator uses the standard 2.2% factor.
How this Calculator Works:
This calculator uses the following simplified methodology:
It takes your input for Years of Service.
It takes your input for Average Annual Salary (last 4 years).
It uses a standard pension factor of 2.2% (0.022) for Regular plan members.
It calculates the estimated annual pension: Years of Service × Average Annual Salary × 0.022
It divides the annual pension by 12 to estimate the Monthly Pension Benefit.
Important Considerations & Disclaimers:
This is an Estimate: This calculator provides an approximation. Your actual IMRF pension benefit may differ based on your specific IMRF plan, contributions, service history, and current IMRF regulations.
Official IMRF Records are Definitive: For an accurate calculation, always refer to your official IMRF benefit statements or contact IMRF directly.
Plan Types: This calculator assumes the standard "Regular" IMRF plan. Different plans (e.g., SLEP) have different pension factors and rules.
Contributions: Employee contributions and employer contributions affect your pension, but this simplified model focuses on the core benefit calculation.
Cost of Living Adjustments (COLAs): This calculator does not factor in potential future Cost of Living Adjustments (COLAs), which may be applied to your pension after retirement.
Integration with Social Security: Some plans might have provisions related to Social Security integration, which is not modeled here.
Use this tool as a helpful guide for preliminary retirement planning, but always consult official IMRF resources for precise figures.
function calculateIMRFPension() {
var yearsOfServiceInput = document.getElementById("yearsOfService");
var avgAnnualSalaryInput = document.getElementById("avgAnnualSalary");
var resultDiv = document.getElementById("result");
var yearsOfService = parseFloat(yearsOfServiceInput.value);
var avgAnnualSalary = parseFloat(avgAnnualSalaryInput.value);
// Clear previous results and error messages
resultDiv.innerHTML = 'Your estimated monthly pension will appear here.';
yearsOfServiceInput.style.borderColor = '#ccc';
avgAnnualSalaryInput.style.borderColor = '#ccc';
var errors = [];
if (isNaN(yearsOfService) || yearsOfService < 0) {
errors.push("Years of Service must be a non-negative number.");
yearsOfServiceInput.style.borderColor = 'red';
}
if (isNaN(avgAnnualSalary) || avgAnnualSalary 0) {
resultDiv.innerHTML = " + errors.join(") + ";
return;
}
var pensionFactor = 0.022; // Standard IMRF Regular plan factor (2.2%)
var annualPension = yearsOfService * avgAnnualSalary * pensionFactor;
var monthlyPension = annualPension / 12;
// Format the result to two decimal places for currency
var formattedMonthlyPension = monthlyPension.toFixed(2);
resultDiv.innerHTML = 'Estimated Monthly Pension: $' + formattedMonthlyPension + ";
}