You will find the savings withdrawal calculator to be very flexible. While it is most frequently used to calculate how long an investment will last assuming some periodic, regular withdrawal amount, it will also solve for the " Starting Amount", "Annual Interest Rate" or "Regular Withdrawal Amount" required if you want to dictate the duration of the payout. That is, if the withdrawals must last for say 25 years, it will calculate one of these other three values.
Enter any three values and enter a "0" (zero) for the one unknown value.
A note or two about "Compounding Frequency". Selecting he "Exact/Simple" option sets the calculator so it will not compound the interest. Also, the exact number of days between withdrawal dates is used to calculate the interest for the period. The "Daily" option uses the exact number of days between dates, but daily compounding is assumed. (The interest earned each day is added to the principal amount each day.) The "Exact/Simple" compounding option is the most conservative setting. That is, using it will result in the lowest future value. Daily compounding will result in nearly the greatest future value (except for "Continuous Compounding".
The other compounding frequencies are based on periods of time other than days. Each period is assumed to be of equal length for the purposes of interest calculations. That is, assuming a balance of $10,000, the interest earned for January will be the same interest earned for February given the same interest rate.