Illinois · Free tool
Illinois TRS Pension Calculator
The Teachers' Retirement System of Illinois (TRS) calculates your pension with one formula: 2.2% multiplied by your years of creditable service multiplied by your final average salary. Enter your numbers below for an estimate.
Enter your numbers. The percentage is pre-filled with the Illinois TRS factor that fits most members; adjust it for your tier or plan.
Illinois TRS final average salary is the average of your 4 highest consecutive years (Tier 1) or 8 highest consecutive years (Tier 2). Tier 2 also caps pensionable salary (about $145,650 in 2026). The 75% maximum is reached near 34 years. Confirm your tier and numbers with TRS.
Your estimated Illinois TRS pension
Updates as you type.
Educational estimate only, not financial advice. Uses a simplified Illinois TRS formula and your inputs; your real benefit varies by tier, plan, service, and salary rules.
How the Illinois TRS formula works
Illinois TRS uses a single benefit factor for both tiers: 2.2% per year of creditable service, multiplied by your final average salary. Thirty years of service, for example, is worth about 66% of your final average salary. The maximum benefit is capped at 75% of final average salary, which you reach at roughly 34 years.
The big difference is the tier. Tier 1 (first contributed before January 1, 2011) averages your four highest consecutive years within your last ten. Tier 2 (first contributed on or after January 1, 2011) averages your eight highest consecutive years, faces an annual pensionable-salary cap of about $145,650 in 2026, and requires age 67 for unreduced benefits. Same 2.2% factor, lower final average salary for most Tier 2 members. Use the full Teacher Retirement Calculator to combine your pension with your 403(b)/457(b) and Social Security, or read what the WEP and GPO repeal means for teachers.
Questions
How is an Illinois TRS pension calculated?
Illinois TRS multiplies 2.2% by your years of creditable service by your final average salary. For example, 30 years at a $75,000 final average salary is 2.2% × 30 × $75,000 = $49,500 per year. The benefit is capped at 75% of final average salary, reached at about 34 years.
What is the difference between Tier 1 and Tier 2 in Illinois TRS?
Both tiers use the same 2.2% factor. Tier 1 members (first contributed before January 1, 2011) average their 4 highest consecutive years and can retire earlier. Tier 2 members (on or after January 1, 2011) average 8 highest consecutive years, face an annual salary cap of about $145,650 in 2026, and need age 67 for unreduced benefits.
Do Illinois teachers get Social Security too?
Most Illinois public school teachers do not pay into Social Security through their teaching job, so their TRS pension is their primary retirement income. If you earned Social Security from other work, the Windfall Elimination Provision and Government Pension Offset that used to reduce it were repealed in January 2025, so you now keep your full benefit.