Money Market Account Calculator - APY Growth Forecast

Project a money market account balance, deposits, earned interest, and fee impact from APY, contributions, compounding, and term.

Enter a starting deposit, APY, years, optional monthly additions, a minimum-balance fee rule, and compounding to project the ending balance.

Money Market Account Calculator
Grow a money market balance with APY, monthly deposits, and optional low-balance fees.

About the Money Market Account Calculator

A money market account is a deposit account that typically pays a variable APY and may charge a monthly fee if the balance falls below a minimum. This calculator starts with an initial deposit, converts the entered APY into a monthly growth factor using the selected compounding frequency, then applies monthly deposits and optional fees for each month of the term. The monthly rate is (1 + APY/100/n)^(n/12) − 1, where n is 1, 4, 12, or 365. Each month the balance becomes Balance × (1 + monthly rate) + monthly deposit. If a monthly fee is entered and the balance after that growth step is below the minimum-balance requirement, the fee is subtracted and accumulated. Ending interest is Ending balance − Total deposits + Total fees, so fees do not masquerade as negative yield. Total deposits equal the opening amount plus monthly deposit × months. That loop is a planning model, not a bank statement. Actual money market APYs can be tiered, promotional, or changed at any time. Compounding may be daily with monthly crediting. Some banks waive fees with a checking relationship or electronic statements. Withdrawal limits are looser than they were under old Regulation D, but a bank can still restrict convenient transfers. FDIC insurance, excess-balance sweeps, and brokerage money-market funds are different products; this page models a deposit-style balance, not a fund NAV. Use the calculator to see whether a $5,000 opening deposit plus $200 a month at 3.5 percent APY outruns fees, or whether a low starting balance under a high minimum will be nickeled by monthly charges. Keep APY and compounding consistent: if the bank quotes APY, daily compounding is the usual match. If a bank uses balance tiers, run the calculator once per tier rather than blending rates. Confirm live rates, fee schedules, and insurance coverage with the institution before moving cash.

Money Market Account Calculator Examples

Money market projections with monthly deposits and optional fees.

InputsResultNote
Start $5,000; 3.5% APY; 3 years; $200 monthly; minimum $1,000; fee $0; daily compoundingEnding $13,134.03; deposits $12,200.00; fees $0.00A funded account that stays above the minimum, so no fee is charged.
Start $1,000; 0% APY; 1 year; $100 monthly; minimum $5,000; fee $2Ending $2,176.00; fees $24.00The balance stays below the minimum all year, so the $2 fee hits every month.
Start $10,000; 4% APY; 2 years; $0 monthly; minimum $0; fee $0; daily compoundingEnding $10,832.82; deposits $10,000.00; interest $832.82A lump-sum deposit with no additions and no fees.

How to Use the Money Market Account Calculator

  1. Enter the opening deposit, APY, and time period in years.
  2. Add optional monthly deposits, the minimum balance that triggers fees, and the monthly fee if any.
  3. Choose compounding frequency. Daily is typical when the bank quotes APY.
  4. Select Calculate to view ending balance, total deposits, interest earned, and fees.
  5. Use Reset before comparing another rate or fee schedule.

Money Market Account Calculator FAQ

Is APY the same as APR here?

Enter the annual percentage yield the bank quotes. The calculator converts that APY into a monthly factor using the compounding frequency you select.

When is the monthly fee charged?

Only when a fee is entered and the balance after that month’s growth and deposit is below the minimum-balance requirement. If the balance stays above the minimum, fees stay at zero.

Does the rate stay fixed for the whole term?

In the model, yes. Real money market APYs can change at any time, so treat a multi-year projection as a what-if, not a locked yield.

Are money market funds included?

The math can approximate a stable $1 fund if you ignore NAV wobble, but brokerage funds have different fees and are not bank deposits. Confirm SIPC versus FDIC coverage separately.

Why can interest be less than APY times years?

Fees, mid-year deposits, and compounding conventions all change earned interest. Compare the interest line with total deposits rather than multiplying APY by the opening balance only.