Retirement Corpus: How to Calculate the Money You Need
A practical guide to calculating retirement corpus using inflated expenses, existing savings, SIP, EPF, NPS, gratuity and post-retirement withdrawals.
Direct answer
Retirement corpus is calculated by inflating today’s monthly expenses to retirement age, estimating the corpus needed to fund retirement years, and subtracting existing savings, SIPs, EPF, NPS and gratuity. The remaining gap tells you how much more to invest.
Step 1: Estimate retirement expenses
Start with current monthly essential expenses. Do not simply use today’s expense for 25–30 years later. Inflation turns ₹50,000 per month into a much larger future requirement.
Step 2: Estimate required corpus
The calculator capitalises inflated monthly expenses over the retirement period using a conservative post-retirement real return. It accounts for withdrawals at the start of each month and inflation during retirement.
Step 3: Add what you already have
- Existing savings and investments.
- Ongoing monthly SIP or step-up SIP.
- Expected EPF corpus.
- Expected NPS corpus after annuity assumptions.
- Expected gratuity.
Step 4: Convert the gap into action
If projected corpus is lower than required corpus, increase monthly investment, extend the horizon, reduce expected retirement lifestyle, or improve expected returns within a suitable risk profile. A step-up SIP can make high targets more achievable.
After retirement
Use the SWP calculator to model monthly withdrawals from mutual fund investments. For NPS, model the annuity portion separately. Keep emergency and medical buffers outside the core retirement corpus.
This guide follows the same assumptions as SmartFintool’s retirement calculator. Last reviewed: 24 August 2026.
Article FAQ
How much retirement corpus is enough?
It depends on monthly expenses, inflation, years to retirement, life expectancy and post-retirement returns. There is no one-size-fits-all number.
Can EPF and NPS be included?
Yes. Enter expected EPF, NPS and gratuity amounts in the optional retirement benefits section.
Should I use SWP after retirement?
SWP can be one way to generate income, but tax, market risk and withdrawal rate matter.
Run the numbers yourself
Use the free SmartFintool calculators to apply this guide to your own money.