Retirement Corpus Calculator
Start from what you spend today. The calculator projects it to your retirement date, works out the corpus needed to fund it for as long as you specify, and the monthly SIP that could build that corpus.
Your numbers
What this calculator shows
The calculator answers three linked questions. What will your current monthly expenses be by the time you retire? How large a corpus would you need on retirement day to keep paying those expenses — rising with inflation each year — for as many years as you enter? And what monthly SIP, at your assumed pre-retirement return, could build that corpus?
The formula, in plain words
First, monthly expense at retirement = today's expense × (1 + inflation)^years to retirement. Twelve of those is the first year's withdrawal. The real return is (1 + return after retirement) ÷ (1 + inflation) − 1. The corpus is the present value of withdrawals that rise with inflation, taken at the start of each year: first-year withdrawal × [(1 − (1 + real return)^−years) ÷ real return] × (1 + real return). The SIP figure then uses the goal-planner formula on that corpus.
A worked example
Someone spending ₹50,000 a month, retiring in 25 years at 6% inflation, would need about ₹2.15 lakh a month at retirement. For that spending to last 25 years with the corpus earning 8%, the calculator estimates a corpus of roughly ₹5.2 crore — and, at an assumed 11% pre-retirement return, a monthly SIP of about ₹32,600 starting now.
Assumptions and limits
- Steady inflation and returns; real ones vary, and returns are not guaranteed.
- Expenses are assumed to stay the same in real terms; health costs often rise faster later in life.
- No taxes, no other income, and the corpus is fully used up by the end of the period.
Frequently asked questions
Why is the corpus so large?
Two reasons: expenses grow with inflation for many years before you retire, and the corpus must then fund rising expenses for decades. Small changes to inflation or years in retirement move the number a lot.
What is the 'real' return?
The return after inflation. If the corpus earns 8% while expenses rise 6%, it effectively grows only about 1.9% a year in today's terms. That real rate is what determines how long the money lasts.
Does this include EPF, NPS, or pension income?
No. If you expect other income in retirement, subtract it from the monthly expenses you enter so the calculator only plans for the gap.
These figures are estimates for learning and planning, not investment, tax, or legal advice. Returns on market-linked investments are not guaranteed, and real outcomes depend on fees, taxes, timing, and actual returns. See our disclaimer.