Retirement Corpus Calculator
By Santaji GadepatilinUpdated October 27, 2026
Corpus needed at retirement vs Years until retirement (years) — other inputs held at your current values.
How to use this calculator
Enter your current annual expenses, expected inflation, years until retirement and a withdrawal rate. The calculator projects your expenses at retirement and the corpus needed to fund them.
Formulas
Expenses at retirement = E × (1 + inflation)t
Corpus = Expenses at retirement ÷ withdrawal rate
Worked example
Annual expenses of 600,000 today, 6% inflation, retiring in 25 years, 4% withdrawal rate:
- Expenses at retirement = 600,000 × 1.06²⁵ = 2,575,122 per year
- Corpus needed = 2,575,122 ÷ 0.04 = 64,378,061
That large figure shows how strongly inflation compounds over decades.
Withdrawal rate and corpus multiple
| Withdrawal rate | Corpus = expenses × |
|---|---|
| 5% | 20 |
| 4% | 25 |
| 3.5% | 28.6 |
| 3% | 33.3 |
Important assumptions
- Investments keep growing during retirement, roughly matching inflation plus the withdrawal rate.
- Healthcare costs often rise faster than general inflation.
- Pensions or rental income reduce the corpus needed — subtract them from expenses.
This is a planning estimate, not financial advice. Consider speaking to a qualified financial planner.
Frequently asked questions
What is the 4% rule?
A guideline from US studies of historical returns — withdrawing 4% of your savings in the first year, then adjusting for inflation, has historically lasted about 30 years. It equals saving 25 times your annual expenses.
Should I use 4% or a lower rate?
Many planners suggest 3–3.5% for early retirement, longer lifespans or countries with higher inflation. A lower rate means a larger corpus but more safety.
How do I build this corpus?
Use the SIP calculator — press × on Monthly investment and type the corpus as your target future value.