Start with the money you put in
A projection begins with two things you control in the worksheet: the starting balance and regular deposits. Interest is a separate line. Comparing the two helps you see whether a plan relies mostly on saving or on an optimistic rate.
The rate needs a definition
This tool accepts a nominal annual interest rate and a compounding frequency. It converts that into an equivalent monthly rate so monthly deposits can be modelled consistently. This is a planning convention; a bank may calculate daily interest on changing balances and credit it monthly.
Timing changes the result
A deposit made at the beginning of a month earns one additional month of interest compared with the same deposit made at month-end. The timing switch makes that choice explicit. Keep the setting the same when comparing offers.
A projection is not a promise
The rate is held constant for the entire illustration. A promotional offer may expire, an account fee may change, and deposits may stop. Try a lower rate, then inspect the monthly ledger before treating the headline as your plan.
Take this little checklist with you.
- Check whether a quoted rate is nominal or effective.
- Read what happens after a promotion ends.
- Use the monthly ledger to reconcile deposits and interest.
Check your print preview before saving or printing.