Find what APY you need to hit a specific savings goal.
How often interest is added (daily, monthly, quarterly).
Compare a standard savings account (0.01% APY) against a High-Yield Savings Account (4.00%+ APY). The spreadsheet will show a dramatic "hockey stick" curve where the gap between the two grows exponentially over 10+ years. The "Wait" Cost
The real rate of return including compounding.