Most TSP growth calculators ask you to guess a return rate. This one defaults to the G Fund's real historical average since 2005: a deliberately conservative, government-backed rate that has never posted a losing year, so your starting projection reflects the safest floor rather than an optimistic guess. From there you can set it to any single fund's actual rate with the preset buttons below or override it with any rate you'd like to test.
This calculator runs entirely in your browser. Nothing you enter is saved, transmitted, or seen by ThriftTrading. Historical averages are computed from TSP's own published share price history; they describe the past, not a guarantee about the future.
Many free TSP calculators default to a made-up assumption like "7% growth" with no real basis. This one defaults to the G Fund's actual historical rate, pulled from the same verified TSP share-price history used throughout this site: a conservative, guaranteed-floor starting point rather than an optimistic guess. The per-fund preset buttons below then let you swap in any single fund's actual historical rate to see how a 100% G Fund projection differs from a 100% C Fund one.