Money Market Account (MMA) Calculator

Worked example

A balance of $10,000 with tier 1: $0–$10,000 @ 4.00%/year and tier 2: above $10,000 @ 4.50%/year, $10/month fee:

• First month's interest = $10,000 × 4.00% ÷ 12 = $33.33.
• Net after fees = $33.33 − $10 = $23.33.
• Break-even balance (interest = $10 fee): $10 ÷ (4.00% ÷ 12) = $3,000.
• Effective APY of 4.00% with monthly compounding = (1 + 0.04/12)¹² − 1 = 4.0742%.

All figures above were independently recomputed and match the calculator engine.

Formulas used

• Monthly interest = balance × (annual rate ÷ 12). "Whole balance" mode: the rate of the tier your balance falls in applies to the whole balance. "Marginal" mode: each balance portion uses its own tier's rate.
• Effective APY = (1 + monthly rate)¹² − 1.
• Break-even: the minimum balance S such that S × monthly rate(S) ≥ monthly fee.
• Projection: deposits are assumed to arrive at the start of the month; interest is computed on the balance after the deposit; fees are deducted at month end.

These figures are educational illustrations and not financial advice. Each bank's product has different minimum-balance requirements, fees, and tier-application methods.

Frequently asked questions

What is a money market account (MMA)?

A money market account (MMA) is an interest-bearing bank deposit account, usually with balance-tiered interest rates. It combines features of savings (interest) and checking (usually you can write checks or use a debit card). In the United States, funds in an MMA at an FDIC member bank are insured up to $250,000 per depositor, per bank, per ownership category (source: FDIC.gov; data as of October 9, 2026). This calculator simulates the interest — the results are educational estimates, not financial advice.

How is a money market account different from a regular savings account?

Both are bank deposit accounts and both can be FDIC-insured, but MMAs generally offer higher interest, often require larger minimum balances, and usually provide check or debit-card access. Regular savings accounts usually have no high minimum-balance requirements but pay lower interest. Also watch the monthly maintenance fee: high interest can be eaten away by fees on a small balance — use this calculator's break-even solver mode to compute the minimum balance.

Is a money market ACCOUNT the same as a money market FUND?

No — these are two different products despite the similar names. A money market account is a bank deposit account and can be FDIC-insured up to $250,000 per depositor per bank. A money market fund is a mutual fund (an investment product) regulated by the SEC: it is NOT a bank deposit, is NOT insured or guaranteed by the FDIC or any government agency, and its value can fall — such funds can 'break the buck' (historical example: one large fund fell to $0.97 per share in 2008). Always check the product type before placing funds. This calculator only models the account, not the fund.

How do tiered interest rates work?

Banks set several interest tiers based on balance, e.g., $0–$10,000 earns 4.00% and above $10,000 earns 4.50%. The common practice at US banks: the rate of the tier your balance falls in applies to the WHOLE balance (not per portion). That means a $10,000 balance earns 4.00% on the entire $10,000, i.e., $33.33 per month before fees. This calculator offers two modes for transparency: 'whole balance' (common bank practice) and 'per balance portion' (marginal). A balance exactly at a tier boundary uses the lower tier.

Is there a limit on the number of monthly withdrawals from a money market account?

There is no longer a federal limit. Regulation D used to limit 'convenient' withdrawals from savings/money market accounts to a maximum of 6 per month, but the Federal Reserve removed that limit through an interim final rule effective April 24, 2020 — banks may, but are not required to, lift enforcement of the limit. So as of October 9, 2026 the limit is each bank's own policy: some banks still set limits or charge per excess withdrawal. Check your bank's account agreement.

How is this calculator different from an APY calculator?

An APY calculator answers the general interest-rate conversion question: converting a nominal rate to APY (or vice versa) for any product. This calculator specifically simulates a money market account: balance-tiered interest, monthly maintenance fees, a break-even balance solver, and a 12-month projection with regular deposits. For general rate conversion, use our APY calculator at /tools/apy-calculator/.

Is money market account interest taxable?

Yes, generally it is taxable — but the rules depend on the country. In the US, bank interest is taxable income in the year received (IRS Topic 403); interest of $10 or more is usually reported by the bank via Form 1099-INT. In Indonesia, savings/deposit interest is subject to 20% final income tax withheld by the bank (PP 131/2000 in conjunction with PP 123/2015), unless the savings/deposit balance does not exceed Rp7.5 million. Rules can change; figures above as of October 9, 2026. This is general information, not tax advice — consult a tax professional for your case.

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