Money Market Account Calculator
Estimate balance growth in a money market deposit account (MMA), using a stated APY and monthly additions.
FREE ONLINE CALCULATOR
Money Market Account Calculator
Change the settings below to calculate your result. You can check the assumptions further down this page.
Monthly growth factor = (1 + APY) ^ (1 / 12).
How to use this money market account calculator
Enter your opening balance, APY, regular monthly deposit and years. The tool converts APY to a consistent monthly effective growth factor.
Formula and calculation method
Monthly growth factor = (1 + APY) ^ (1 / 12).
Worked example
A deposit account paying 4% APY has a modeled effective yearly increase of 4% before tax, fees or withdrawals.
Understanding the result
Money market account balances are commonly described using APY, which already represents a year of compounding. This calculator uses that APY to create an effective monthly growth factor for contributions at the end of each month.
When to use this calculator
Before comparing accounts, consider balance thresholds, changing advertised yields and access rules. A money market deposit account is not the same product as a money market mutual fund, even though their names sound similar.
What the results do not include
Actual APY can change and account fees, balance tiers and withdrawal restrictions may affect returns.
Frequently asked questions
Does MMA mean mixed martial arts here?
No. In this finance hub, MMA means money market account.
How is APY different from nominal rate?
APY already accounts for the effect of compounding over a year.
For education and estimates only. Check any contractual, tax, banking or employment terms that apply to your situation. The calculations are not financial advice or guaranteed returns.