Project high-yield savings account balances and interest at your stated APY.
Overview
High-yield savings accounts (HYSA) compete on APY, but your personal outcome still depends on how much you keep deposited and whether you add money consistently. Small APY gaps matter more on larger balances held for multiple years.
This calculator focuses on the mechanics: daily compounding on the balance you enter, plus optional monthly additions. It helps you compare a HYSA projection against checking cash or lower-yield savings sitting idle.
Not affiliated with CIT Bank/Merrill. Confirm tier rates, balance minimums, and transfer limits on official product pages before relying on any projection.
Steps
Current or planned HYSA principal.
Use the tier APY that matches your expected balance.
Add recurring transfer amount if applicable.
Choose months or years to project.
See how much is contributions versus yield.
Model rate cuts for conservative planning.
Math
Ending balance = compound daily(APY, balance, time) + future value of deposits
APY converts to a daily rate; each day applies to the running balance including posted deposits.
Worked cases
Daily compounding, no further deposits
Interest roughly $2,600 over two years.
Build balance with deposits and yield
Ending balance near $10,500 after 5 years (approx.).
Side-by-side projections
Shows cushion needed if rates drop.
Why use this
Questions