Retirement Corpus Calculator

Work out the nest egg you need on the day you retire. Enter your ages, today's expenses and your return assumptions, then press Calculate to see the corpus and how it draws down.

Written by TopicDrill Editorial Team·Updated June 2026

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Corpus drawn down in retirement

Remaining corpus

How the retirement corpus calculator works

The hardest part of planning for retirement is naming a number. This tool builds that number from the spending you already understand. It takes your monthly expense in today's money, ages it forward to your retirement date using inflation, and then asks how large a pot is needed to fund those rising withdrawals for the years you expect to be retired.

The shaded chart shows the corpus being spent down year by year. It starts at the full amount, dips as each withdrawal is taken, and is sized so that the balance lands near zero around your assumed life expectancy rather than running dry years too soon.

A worked example

Suppose you are 32, plan to retire at 60, and expect to live to 85. You spend $3,000 a month today. With 5 percent inflation, that same lifestyle costs roughly $11,800 a month by the time you retire. Funding 25 years of those inflation-rising withdrawals at a 7 percent post-retirement return calls for a corpus in the region of two and a half million dollars. Lowering your retirement age or raising your spending pushes that figure up quickly.

Things to keep in mind

The result is only as good as the assumptions behind it, and small changes to inflation or returns move the target a lot. Build in a margin and revisit the plan every few years. For a neutral primer on retirement saving, see Investor.gov. Once you know your target, our retirement savings calculator shows how much to set aside each month to get there.

Frequently asked questions

What is a retirement corpus?

A retirement corpus is the single pool of savings you aim to have on the day you stop working. It has to be big enough that the withdrawals you take from it, plus the returns it keeps earning, cover your living costs for the rest of your life.

How does this calculator size the corpus?

It first inflates your current monthly expense to the value it will have on your retirement date. It then treats retirement spending as a stream of withdrawals that rise with inflation each year, and discounts that stream at your post-retirement return to find the lump sum needed up front.

Why do pre and post retirement returns differ?

Before retiring you can hold more growth assets, so the pre-retirement return is usually higher. After retiring most people shift toward safer, lower-yielding holdings to protect the corpus, so the post-retirement return entered here is typically a bit lower.

Does the corpus account for inflation?

Yes. Inflation is applied twice. It grows your expense from today to your retirement date, and it raises each yearly withdrawal during retirement so your spending power stays roughly level rather than shrinking over time.

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