How to use this calculator
- Current age and retirement age. The gap between them is the number of years you have to save.
- Current savings. Enter what you have already put aside for retirement.
- Monthly contribution. Enter what you plan to add each month until you retire.
- Expected yearly return. Enter the average yearly growth you expect on your savings.
- Inflation rate. Enter the yearly rise in prices you expect.
The calculator shows your balance at retirement, the same balance in today's money, an estimated yearly and monthly income, your total contributions and a chart of the balance by age.
Worked example
These are the starting values in the calculator above and the results they give. Change any input to see your own numbers.
- Current age
- 35
- Retirement age
- 65
- Current savings
- $40,000
- Monthly contribution
- $600
- Expected yearly return
- 6%
- Inflation rate
- 2.5%
- Balance at retirement
- $843,612
- In today's money
- $402,186
- Estimated yearly income
- $16,087
- Estimated monthly income
- $1,341
- Total contributions
- $256,000
How the retirement estimate is calculated
The balance at retirement comes from two parts. Your current savings grow at the expected return, compounded monthly, until retirement age. Each monthly contribution also grows from the month you make it. The two are added together.
Prices rise over time, so a dollar at retirement will buy less than a dollar now. To show the balance in today's money, the calculator divides it by the growth in prices over the same years. This figure is easier to judge, because you can compare it with what things cost today.
The income estimate uses the 4% rule. It takes 4% of the balance in today's money as yearly income and divides that by 12 for the monthly figure. For example, 4% of $500,000 is $20,000 a year.
B = S × (1 + i)^N + C × ((1 + i)^N − 1) ÷ i; Real B = B ÷ (1 + f)^Y; Yearly income = 0.04 × Real B- B
- balance at retirement
- S
- current savings
- C
- monthly contribution
- i
- monthly return (yearly return ÷ 12, as a decimal)
- N
- months until retirement
- f
- yearly inflation rate as a decimal
- Y
- years until retirement
- Real B
- balance in today's money
What the 4% rule means and what moves the result
The 4% rule is a rough planning rule of thumb. The idea is that withdrawing about 4% of your savings in the first year of retirement, then adjusting for inflation, has often been sustainable over a long retirement in past studies. It is not a guarantee. Real results depend on market returns, how long retirement lasts, fees, taxes and how spending changes. Treat the income figure as a starting point for planning.
You can also run the rule backward: yearly spending multiplied by 25 gives a rough savings target. Spending of $40,000 a year points to about $1,000,000.
The inputs that matter most:
- Years until retirement. More time means more contributions and more compounding.
- Return minus inflation. The gap between the two drives the result in today's money.
- Monthly contribution. This is the input you control most directly.
The model assumes steady returns and level contributions and does not include pensions or other income. See how compound interest works, or test one target with the savings goal calculator.
Frequently asked questions
How much do I need to retire?
It depends on how much you expect to spend each year and what other income you will have. One rough approach is to multiply the yearly spending your savings must cover by 25, which is the 4% rule in reverse. That gives a ballpark target only. Your own needs, health, housing costs and retirement length all change the answer.
What is the 4% rule?
The 4% rule is a rule of thumb for retirement spending. It suggests withdrawing about 4% of your savings in the first year and then raising that dollar amount with inflation each year. It comes from studies of past market returns over long retirements. It is a planning guide, not a promise, and some retirees will need to withdraw less.
Why is the balance in today's money lower?
Because prices usually rise over time. The same number of dollars will buy less in the future than it does now. The figure in today's money removes the effect of inflation, so you can compare your retirement balance with present-day costs. The longer you have until retirement and the higher the inflation rate, the bigger the gap.
What rate of return should I assume?
No one knows future returns, so it helps to test a range. Returns depend on how the money is invested, and investments with higher long-term averages also tend to swing more from year to year. Try a cautious rate and a more hopeful one. If the plan only works at the hopeful rate, it may need more saving or more time.
Does this calculator include pensions or government benefits?
No. It only models your own savings and contributions. Any pension, government retirement benefit, rental income or part-time work would be on top of the income shown. To allow for them, subtract that income from the yearly amount you expect to need, then compare what is left with the estimated income from your savings.
This calculator gives estimates for education only. It does not know your full situation and is not financial advice. Reviewed and updated November 15, 2026.