Retirement Planning Calculator

Retirement Planning: Working Out Your Number

By the EMI Cal Hub team · Last updated October 2026

Retirement planning comes down to one question: how much money will you need on the day you stop working, so that it lasts for the rest of your life? This calculator works through that question step by step, using your own assumptions about expenses, inflation and returns.

How the calculation works

1. Future expenses. Your current monthly expenses are grown by inflation until your retirement age. Prices rise over decades, so the same lifestyle will cost much more.
2. Corpus needed. The calculator works out the lump sum required to pay those expenses every month from retirement until your life expectancy, assuming the remaining money keeps earning a return while you withdraw it, and that expenses keep rising with inflation.
3. Existing savings. What you've already saved is grown at your pre-retirement return.
4. The gap. If your savings fall short, the calculator shows the monthly investment needed to close the gap by retirement.

Choosing sensible assumptions

• Inflation: use a long-term average for your country. Even small changes have a large effect over 30 years.
• Return before retirement: a long-term, diversified portfolio can usually take more risk while you're working.
• Return after retirement: most people shift towards safer investments later, so this is usually lower.
• Life expectancy: plan on the long side. Running out of money is a bigger risk than leaving some behind.

If the monthly figure looks too high

Don't be discouraged. You can start with a smaller amount and increase it as your income grows, retire a few years later, reduce expected expenses, or combine several approaches. Starting early is the most powerful lever, because compounding has more time to work.

Revisit your plan every year or two, and whenever your income, family or goals change.