Retirement corpus is the lump sum you need at retirement age to fund your remaining life without active income. The calculator factors in inflation, pre- and post-retirement returns, and gives both the corpus needed and the monthly SIP required to build it.
What is Retirement?
Retirement corpus is the single most important number in personal finance. Underestimate it and you run out of money at 75. Overestimate it and you under-spend in your healthy years. The calculator gives you a realistic answer based on your specific lifestyle and assumptions.
The biggest variable is inflation. ₹50,000/month today buys what ₹2.86 lakh/month buys in 30 years at 6% inflation. The corpus also has to keep growing during retirement to outpace inflation while you withdraw — this is what separates good retirement planning from bad.
The calculator uses a 'real return' approach: it computes the gap between your post-retirement portfolio return (8-9% typical) and inflation (6%), then sizes the corpus so that real, inflation-adjusted withdrawals last for your full retirement period.
Sizing the corpus
Two-step calculation: (1) project today's monthly expense forward to retirement age using inflation, then (2) compute the present-value annuity that funds those inflated expenses over your retirement years at the post-retirement return rate.
The calculator also computes the monthly SIP required (compounding pre-retirement) to build that corpus by retirement age.
- i
- Inflation rate—annual, default 6% for India
- post_R
- Post-retirement return—more conservative; 8% typical
- pre_R
- Pre-retirement return—more aggressive; 12% typical for equity
- t
- Years to retirement—current age to retirement age
- n
- Retirement years—retirement age to life expectancy
How to use this calculator
Seven inputs let you model a realistic retirement plan. Be honest about expenses and conservative on returns.
Set current age and retirement age
60 is the standard retirement age in India. Some plan for 55 (early FIRE), some for 65.
Set life expectancy
Plan for at least 85. Healthier individuals or those with longevity in family should use 90+.
Enter today's monthly expense
Estimate what you'd want to spend monthly in today's terms during retirement. Include healthcare (which inflates faster), travel, and dependents.
Set inflation rate
6% is the conservative average for India. Healthcare and education inflation are higher (8-10%).
Set pre- and post- returns
Pre-retirement: 11-13% if equity-heavy. Post-retirement: 7-9% (debt-heavy for capital protection).
Use cases
Goal-setting at age 30
Working backwards from a comfortable retirement gives you a concrete monthly SIP target — far more motivating than vague 'save more'.
Mid-career rebalancing
At 40, recompute. Your earnings are higher; your time horizon is shorter. Adjust SIP upward.
FIRE (Financial Independence Retire Early)
Use lower expenses (₹30K/month) and earlier retirement (50 or 55). The corpus needed becomes manageable.
Spousal planning
Run twice — once for joint expenses, once for survivor (lower expenses). Plan for the longer life expectancy.
Glossary
- Retirement corpus
- Lump sum needed at retirement to fund living expenses for the rest of your life.
- Real return
- Investment return net of inflation. The number that actually matters for purchasing power.
- Safe withdrawal rate
- The percentage of corpus you can withdraw annually without exhausting it. India: ~3-4% safe; US 4% rule.
- FIRE
- Financial Independence, Retire Early — typically retiring before 60 with a smaller, sustainable corpus.
- Sequence-of-returns risk
- The risk that bad market years early in retirement permanently impair the corpus, even if average returns are fine.