How Long Will Your Money Last in Retirement Calculator

How the Retirement Duration Calculator Works

The retirement duration calculator estimates how long your savings will last by considering your current retirement account balance and your expected monthly expenses. The calculation assumes you withdraw a fixed amount each month from your savings, which is a common approach for retirement planning.

Key Inputs

The calculator requires three main inputs:

1. Current retirement savings: The total amount of money you have set aside for retirement.
2. Monthly expenses in retirement: The amount you expect to spend each month during retirement.
3. Annual withdrawal rate: The percentage of your savings you plan to withdraw each year.

Calculation Process

The calculator uses the following steps to determine how long your money will last:

1. Convert the annual withdrawal rate to a monthly rate.
2. Calculate the total monthly withdrawal amount based on your current savings and the monthly withdrawal rate.
3. Divide your total savings by the monthly withdrawal amount to estimate the number of months your money will last.
4. Convert the number of months to years for a more intuitive understanding.

The Formula Used

The retirement duration is calculated using the following formula:

Where:

• Current Savings: Your total retirement account balance.
• Monthly Expenses: Your expected monthly spending in retirement.

This formula assumes you withdraw a fixed amount each month from your savings. The result is an estimate of how many years your money will last based on your current inputs.

Worked Example

Let's look at an example to see how the calculator works in practice.

Example Scenario

• Current Savings: $500,000
• Monthly Expenses: $3,000

Calculation Steps

1. Divide the current savings by the monthly expenses: 500,000 / 3,000 = 166.67 months.
2. Convert the number of months to years: 166.67 / 12 ≈ 13.9 years.

Based on these inputs, the calculator estimates that your $500,000 in savings would last approximately 13.9 years if you withdraw $3,000 per month.

Key Assumptions

The retirement duration calculator makes several assumptions that may affect the accuracy of your results:

Fixed Monthly Withdrawals

The calculator assumes you withdraw a fixed amount each month from your savings. This is a common approach for retirement planning, but it may not account for changes in your expenses or savings over time.

No Additional Income

The calculation does not account for additional income sources, such as Social Security, pensions, or part-time work. If you expect to receive additional income, you may need to adjust your inputs accordingly.

No Market Fluctuations

The calculator does not account for changes in the value of your investments due to market fluctuations. If your investments lose value, your actual retirement duration may be shorter than the estimate.

No Taxes or Fees

The calculation does not account for taxes or fees that may reduce the value of your savings. If you expect to pay taxes or fees, you may need to adjust your inputs accordingly.