FERSmath
Retirement Planning Made Clear

FERS Math

Sophisticated calculators and trusted financial insights to help you understand exactly where you stand — and what it takes to get where you want to be.

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Retirement Calculators

Built for accuracy. Designed for clarity. Each tool models real-world retirement scenarios.

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High-3 Average Salary Calculator

Calculate your FERS High-3 using OPM's 360-day rule. Enter your full GS grade and step history to find your highest 36-month window.

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GS Salary History Lookup

Pick a grade, step, and locality area to see every year of available pay data and a chart of how the salary has grown.

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TSP Fund Performance

Compare G, F, C, S, I, and Lifecycle fund share prices over any date range since May 2003 on an indexed performance chart.

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TSP Monte Carlo Projection

Enter your current TSP balances and see a range of simulated future outcomes built from real historical fund returns, not a single assumed growth rate.

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FERS Supplement Estimator

Estimate your FERS Supplement — the bridge payment you receive before age 62 that approximates your Social Security benefit.

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TSP Projection Calculator

Project your Thrift Savings Plan balance at retirement based on contributions, agency match, and fund selection.

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FERS Basic Annuity Calculator

Calculate your full FERS basic annuity including survivor benefit options and the impact of retiring before or after age 62.

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Clear, unbiased financial writing — no ads, no sponsored content.

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