Find how much to save monthly to reach a goal within a deadline in Washington.
Calculates the monthly deposit needed in Washington to bridge the gap between what you have (and its growth) and the goal, assuming contributions earn the stated annual return.
PMT
PMT = gap × r / ((1+r)^n − 1)
Estimate — returns not guaranteed.
Raise the return to reduce the deposit, but stay conservative.
Rates are approximate reference values. Local rates, exemptions and rules can differ, so treat the output as a planning figure only.