Project a money market account from opening deposit, APY, monthly contributions, term, and compounding frequency, then compare the final balance with a deposit-only baseline.
Last updated
Also in Saving & Investing
Deposit Account Planning
A money market account calculator estimates how an opening deposit and ongoing monthly contributions may grow at a stated annual percentage yield. It is useful when you want a liquid savings projection that sits between a standard savings account and a longer-term product such as a CD.
A money market account is a deposit account, not a money market mutual fund. The projection here focuses on deposit-account maths: a starting balance, a stated APY, optional monthly contributions, and a compounding schedule translated into growth over time.
That makes the calculator helpful for short- to medium-term cash goals, reserve funds, or a parking place for money that still needs to remain accessible while earning yield.
APY already reflects one year of compounding, so the calculator converts the stated APY into an equivalent nominal annual rate for the selected compounding basis before projecting monthly contributions. It also compares the final result with a deposit-only baseline so you can see how much of the ending balance came from added cash versus growth.
Monthly contributions are treated as end-of-month deposits. That means earlier contributions have more time to earn than later ones, which is why the year-by-year schedule is useful for planning.
APY = (1 + periodic rate)^periods per year - 1
The APY relationship used to translate the stated deposit yield into a compounding basis for the projection.
Ending balance = Growth on opening deposit + Growth on monthly contributions
Breaks the final balance into the starting deposit path and the contribution path.
Suppose you start with 10,000, add 250 each month, and earn 4.50% APY for five years. The calculator shows the projected ending balance, total contributions, total interest, and what the opening deposit alone would have become without the monthly additions.
That baseline comparison is useful because it separates savings discipline from account yield. You can immediately see whether the ending balance is being driven mostly by contributions, by the original deposit, or by the interest earned on both.
This calculator assumes one constant APY, one constant compounding schedule, and month-end contributions. It does not model taxes, fees, minimum-balance rules, transfer limits, teaser rates, or the possibility that the APY changes over time.
Use it as a deposit-planning estimate, then compare it with the specific bank's disclosure and account terms before relying on the projection for a real savings decision.
Further reading
Frequently asked questions
No. A money market account is a bank deposit account. A money market mutual fund is an investment product and does not work under the same deposit-account rules or protections.
Because deposit accounts are commonly quoted using APY, which already reflects the effect of compounding across one year. That makes it a more natural starting point for a savings projection.
No. The currency selector changes how values are shown. The projection uses the same numeric cash flows and rate assumptions either way.
It can help with a first-pass rate comparison, but it does not account for CD early-withdrawal penalties, access constraints, or rate-lock features. Those still need separate review.
Related
These related calculators come from the same leaf category, nearby sibling categories, or the same top-level topic.
Convert a nominal annual rate into APY from the selected compounding frequency, then compare effective yields and ending balances.
Estimate CD maturity value, total interest, and derived APY from an opening deposit, nominal annual rate, term, and compounding frequency.
See how deposits and interest can grow your savings, when you may reach a goal, and how much of the result comes from growth.
Convert APR into APY from the selected compounding frequency, then compare effective yields, rate lift, and ending balances side by side.
