The annuity matrix is a tool used to calculate:
- the withdrawal amount from an annuity based on different rates-of-return and number of withdrawals
- the starting amount (PV) for an annuity based on different interest rates and number of withdrawals
The point of a matrix calculator is that it presents multiple results at one time. This can save you from doing a series of what-if calculations.
Some additional notes:
- Withdrawal at: When the withdrawals start. If the first withdrawal is taken on the day the annuity originates, then select "start-of-period," otherwise select "end-of-period."
- Compound frequency: If the compounding frequency is not specified by the annuity documentation or you don't know it, then select the same value as "withdrawal frequency."
- Step values: By how much to increase the x-axis and y-axis values from their initial values. For example, if you've set the "initial interest rate" to 5% and if you set the "rate step value" to 0.5% then the calculator will set the second value for the interest rate (x-axis) to 5.5%.
On the "Withdrawal Amount" tab you can calculate a matrix of potential periodic withdrawal amounts for a given starting amount (PV) while varying the withdrawal term and interest rate for the annuity (or investment account).
The "Present Value" tab allows you to calculate a matrix of various starting amounts (the present value) that would be required for a given withdrawal amount for different terms (number of withdrawals) and interest rates. In other words, how much do you need to start with to have your investment last for "X" withdrawals at various interest rates.
The "step values" on either tab control by what amounts the interest rate and term are going to increase.
Note: It is not necesssay to clear one calculation before doing the next. You can change one value and recalculate.