General · Unit 4 · future-value annuity

Interest grows, then the deposit adds

Each period: interest grows the balance, then your deposit adds — cashflow is +d (a loan’s is −d).

Savings annuity Period 0
+interest
Interest earned
$0
Balance
+deposit
Your deposit
nOpeningInterestDepositClosing

Amber = interest · teal = deposit. Interest earned = balance − total deposits (when A₀ = 0).

Savings calculator

Run one period first — then free parameters unlock.

This period

Time

n0

Jump recomputes the ledger. Next period still plays interest, then deposit.

Working