Retirement Calculator: Nest Egg and Monthly Savings

About the Retirement Calculator

The Retirement Calculator projects how much you could have saved by the time you retire. Enter your current age, the age you plan to retire, what you have saved so far, what you add each month, the annual return you expect and the annual inflation rate. It shows the nest egg in future money, the same amount in today's money once inflation is taken out, the total you contributed, and the balance at every birthday until you retire.

The second mode works backwards. Choose Find the contribution for a target, enter the nest egg you want in today's money, and the calculator shows the monthly contribution that gets you there. If your current savings already reach the target, it says so.

The calculator uses a fixed return and a fixed inflation rate, with contributions at the end of each month. It ignores taxes, fees, account rules such as 401(k) or IRA limits, employer match, pensions and Social Security, and it does not model withdrawals in retirement. The results are estimates, not financial advice.

How to use it

The formulas

The expected annual return $R$ becomes a monthly rate, and the balance after $n = 12y$ months, with savings $S$ and a monthly contribution $C$, is

$$i = (1 + R)^{1/12} - 1, \qquad FV = S(1 + i)^n + C \cdot \frac{(1 + i)^n - 1}{i}$$

The same amount in today's money, with inflation $\pi$ over $y$ years, and the future value of a target $T$ given in today's money, are

$$\text{today} = \frac{FV}{(1 + \pi)^y}, \qquad T_{\text{future}} = T(1 + \pi)^y$$

Worked examples

• From 30 to 65. 50,000 saved, 500 a month, a 7% return and 2.5% inflation give 1,389,535.89 at 65, which is 585,510.22 in today's money. You contribute 260,000.00 in total.
• The first year. At 31 the balance is 59,690.15, or 58,234.29 in today's money.
• No growth. From 60 to 65 with 10,000 saved and 100 a month at 0% return, the nest egg is 16,000.00.
• Inflation alone. 100,000 kept for 10 years at 0% return with 3% inflation is worth 74,409.39 in today's money.
• A target. For 1,000,000 in today's money at 65, starting at 30 with 50,000, save 1,074.77 a month.

Related calculators

To try different deposit and compounding frequencies, or to solve for the rate or the time, use the Future Value Calculator. To see a balance grow year by year with any deposit, use the Compound Interest Calculator, and to see what past inflation has done to the dollar, use the USD Inflation Calculator.

Privacy

Nothing is uploaded; every calculation runs in your browser and never leaves your device. The figures you type stay on this page and are gone when you close or reload it.

Frequently asked questions