Retirement Corpus Calculator

It tells you the size of the lump sum you'd need on the day you retire to sustain your chosen monthly expense for your full retirement — it does not calculate how many years until retirement or how much to save monthly to get there; for that, use the Retirement Age Calculator.

The corpus has to keep growing while you draw from it, so the calculation uses the gap between your assumed post-retirement investment return and inflation — a larger gap means a smaller corpus is needed to sustain the same monthly expense.

The corpus required grows very large (or the math becomes unstable) when the return-inflation gap shrinks toward zero, since a corpus barely outpacing inflation must be much bigger to last the same number of years.

Enter your expected retirement length — the years from your planned retirement age to your expected life expectancy — not your current age or years until retirement.

The 4% Rule Calculator applies a fixed rule of thumb (25× annual expenses); this calculator instead computes the corpus from your specific assumed return and inflation rates, which can give a different answer depending on those inputs.