18-year-old, $1/year weekly, 30/50/20 split
Inputs
Result
Allowance = $1.00 x 8 = $8.00/week. Annual = $8 x 52 = $416. Savings = $416 x 30% = $124.80/year. Monthly savings = $10.40. At 4% for 60 months: FV = 10.40 x ((1.00333)^60 - 1) / 0.00333 = ~$680.