Money Market
Account Calculator
Project your exact interest earnings with compounding, monthly deposits, inflation adjustment, tax impact, and bank comparisons — all updating live as you type.
Top MMA rates: 4.0–5.0% (Mar 2026)
Shows real purchasing power of gains
Federal + state marginal rate
Fee if below minimum balance
Balance needed to avoid fee
What Is a Money Market Account?
A money market account (MMA) is a federally insured deposit account offered by banks and credit unions that typically pays higher interest than a standard savings account while still keeping your money accessible. It combines features of both a savings and a checking account — you earn competitive interest on your balance, and most accounts allow limited check-writing and debit card access that a regular savings account doesn't offer.
Money market accounts are not the same as money market funds. An MMA at a bank is FDIC-insured up to $250,000 per depositor per institution — your principal is protected. A money market mutual fund is an investment product, not insured, and carries market risk. The distinction matters: this calculator is for bank and credit union money market deposit accounts, not investment funds.
Why MMAs pay more than regular savings accounts: Banks use MMA deposits to fund short-term loans and securities. Because they can typically require notice before large withdrawals (though most don't enforce this in practice), and because they attract larger depositor balances, banks can offer higher rates. Higher minimum balance requirements are the trade-off for the better yield.
How MMA Interest Is Calculated
Money market accounts advertise their rate as APY — Annual Percentage Yield. This is the effective annual return after compounding is applied, and it's what you should use for comparison shopping. The underlying interest rate (APR) is slightly lower; the APY already bakes in the benefit of compounding throughout the year.
Compounding Frequency
Most money market accounts compound interest daily and credit it monthly. "Compounding daily" means your interest is calculated on each day's balance, so any deposits made mid-month immediately start earning. "Credited monthly" means the accumulated daily interest is actually added to your balance once per month. Our calculator lets you select your compounding frequency to match your specific account.
The Compound Interest Formula
The standard formula for compound growth is A = P(1 + r/n)^(nt), where P is principal, r is the annual interest rate (as a decimal), n is the number of compounding periods per year, and t is time in years. With regular monthly contributions, each deposit also begins compounding from the moment it's added. The calculator applies this iteratively month by month to account for your ongoing deposits accurately.
Example: $10,000 at 4.50% APY compounded monthly for 5 years with $500/month added grows to approximately $46,200 — of which roughly $6,200 is pure interest. Without the monthly $500 contributions, the same account yields only $12,494. The $30,000 in contributions accounts for most of the difference, but the compounding interest on all those deposits adds up significantly over time.
Daily vs. Monthly Compounding — Does It Matter?
For most savers, the practical difference between daily and monthly compounding on a money market account is small. On a $25,000 balance at 4.50% APY over one year, daily compounding produces about $3 more than monthly compounding. The APY figure already accounts for this — two accounts advertising the same APY will produce the same end-of-year result regardless of how frequently they compound internally.
What Each Calculator Mode Does
Growth Projection
The core calculator. Enter your initial deposit, APY, compounding frequency, monthly contribution amount, and time horizon. The results show your total balance at the end, total interest earned, and two figures that most calculators skip: your after-tax earnings and your inflation-adjusted balance. These two numbers reveal what your savings are actually worth in real terms.
The inflation-adjusted value answers the question most people should be asking: "If inflation runs at 2.5% and my MMA pays 4.5%, what is my purchasing power gain?" The nominal balance looks bigger than the real gain. After adjusting for inflation, a $46,000 balance five years from now might only represent the equivalent of $40,000 today — still a meaningful gain, but a more honest picture.
Bank Comparison
Enter your deposit amount and time horizon, then compare how the same money performs across different accounts simultaneously. The calculator comes pre-loaded with representative 2026 US rates and lets you edit any value. The comparison table shows the final balance and total interest earned at each institution side-by-side, with the best-performing account highlighted.
The "extra by switching" figure in the stats panel shows the dollar difference between earning the best available rate versus the national average rate — currently around 0.45% at traditional banks. On a $25,000 deposit over five years, the difference between 4.5% and 0.45% APY is roughly $5,000 in additional earnings. This is a powerful argument for moving idle savings from a big bank to a high-yield online MMA.
Tiered Rates
Many money market accounts offer tiered interest rates — higher APYs for higher balance levels. For example, a bank might pay 2.00% on balances under $10,000, 3.50% on $10,000–$24,999, 4.50% on $25,000–$99,999, and 5.00% on $100,000 and above. The tiered mode lets you enter your bank's specific tiers and shows which tier your balance falls in, what you're currently earning, and how much more you'd earn by reaching the next tier.
Goal Planner
Work backward from a target. Enter your savings goal (for example, $50,000 for a home down payment), your starting deposit, your APY, and your planned monthly contribution. The calculator tells you exactly how many months it will take to reach that goal — and shows how much faster you'd get there by adding extra monthly contributions, visualized through the slider comparison.
MMA vs. HYSA vs. CD — Which Is Right for You?
Money market accounts compete with two close alternatives: high-yield savings accounts (HYSAs) and certificates of deposit (CDs). The right choice depends on how long you can leave the money untouched, whether you need occasional access, and how much you value rate certainty versus flexibility.
| Feature | Money Market Account | High-Yield Savings | Certificate of Deposit |
|---|---|---|---|
| Typical APY (2026) | 3.50–5.00% | 4.00–5.00% | 4.00–5.30% (1yr) |
| Rate Type | Variable | Variable | Fixed for term |
| Liquidity | High (limited transactions) | High (limited transactions) | Low (penalty to withdraw early) |
| Check writing | Usually yes | No | No |
| Debit card access | Sometimes | Rarely | No |
| Minimum balance | Often $1,000–$25,000 | Usually $0–$1 | Often $500–$1,000 |
| FDIC insured | Yes (up to $250K) | Yes (up to $250K) | Yes (up to $250K) |
| Best for | Emergency fund + yield | Simple high yield savings | Money you won't need for 1–5 years |
For most people building an emergency fund or saving for a near-term goal, the MMA or HYSA is the better choice — the flexibility to access funds without penalty is worth slightly less yield in most scenarios. CDs make sense when you're confident you won't need the money for a defined period and you want to lock in a guaranteed rate before expected rate cuts.
You want better-than-savings rates, occasional check-writing access, and a tiered structure that rewards higher balances. Good for emergency reserves above $10,000.
You want maximum simplicity, no minimum balance requirement, and the same or very close APY to an MMA. Most online HYSAs now match or beat MMA rates.
You have a defined timeline (6 months to 5 years), want rate certainty, and won't need to touch the money. CDs can beat MMA rates for committed deposit terms.
Traditional big-bank savings accounts currently pay an average of 0.45% — nearly ten times less than competitive MMAs. Idle money in these accounts loses real purchasing power to inflation every year.
Taxes on Money Market Interest
Interest earned in a money market account is taxable as ordinary income in the year it's credited to your account — not when you withdraw it. Your bank will send you a Form 1099-INT for any year in which you earned $10 or more in interest. You report this on your federal income tax return and pay federal taxes plus any applicable state income taxes.
The effective tax bite depends on your marginal rate. At a 22% federal rate plus 5% state tax, you're keeping about 73 cents of every dollar in interest earned. On $2,000 in annual MMA interest, that's a $540 tax bill — a meaningful reduction from the headline yield. This is why our calculator includes a tax rate field: the "after-tax yield" is the number that actually hits your bank account.
Tax-sheltered alternative: If you're saving for retirement, you can often hold money market funds inside a Roth IRA or traditional IRA — where interest compounds tax-free or tax-deferred. For long time horizons, the compounding benefit of sheltering MMA-like returns from annual taxes can be substantial. The trade-off is that retirement accounts limit annual contributions and impose withdrawal restrictions.
What the After-Tax Yield Calculation Shows
Our calculator computes after-tax interest by multiplying total gross interest by (1 − your marginal tax rate). This is a simplified estimate — actual tax liability depends on your total income, filing status, deductions, and state. But for planning purposes, it gives you a far more accurate picture of your real earnings than the gross APY alone.
FDIC Insurance and the $250,000 Limit
Money market accounts at FDIC-member banks are insured up to $250,000 per depositor, per insured bank, per ownership category. This means if your bank fails, the federal government guarantees your deposits up to that limit. Credit unions offer equivalent protection through the NCUA (National Credit Union Administration) with the same $250,000 per-member coverage.
The coverage applies per ownership category, which creates opportunities to extend protection beyond $250,000 at the same institution. A married couple can have individual accounts, a joint account, and retirement accounts at the same bank — each category carries its own $250,000 limit. A couple with optimal structuring can insure over $1 million at a single FDIC-member institution.
Our calculator shows a warning when your projected balance approaches or exceeds $250,000, because accumulating beyond this threshold at a single institution puts some funds at risk in the unlikely event of a bank failure. If your balance is approaching this level, consider spreading deposits across multiple FDIC-insured institutions, using the CDARS network, or exploring Treasury bills as an alternative.
How to Get the Best MMA Rate in 2026
Look Beyond Your Current Bank
The biggest single factor in your MMA rate is whether you're shopping at all. Traditional big banks — the ones with branches on every corner — pay a fraction of what online-only institutions offer. In early 2026, the national average savings rate hovers around 0.45%, while competitive online MMAs regularly offer 4.0–5.0% APY. On a $20,000 balance, that's the difference between earning $90 per year and earning $900.
Understand the Minimum Balance Requirements
Many high-yield MMAs require a minimum balance — often $1,000 to $10,000 — to earn the advertised APY. Falling below the minimum typically triggers either a lower (sometimes much lower) rate or a monthly maintenance fee. Before opening an account, verify the minimum balance requirement and confirm your deposit will comfortably stay above it, factoring in any months where you might need to withdraw funds.
Watch for Rate Tiers
Tiered-rate accounts can work in your favor if you're building a larger balance. If a bank pays 3.5% on $10,000–$24,999 and 4.5% on $25,000+, getting your balance to that threshold unlocks meaningfully better returns. The tiered rate mode in this calculator lets you model exactly how much extra interest you'd earn by reaching the next tier — sometimes the answer is hundreds of dollars per year.
Check for Introductory Offers
Some banks offer promotional APYs for the first few months to attract new deposits. These are worth taking advantage of if you'll move the money elsewhere when the promotion ends, but don't let an intro rate lock you into an account with a poor regular rate. Model both the promotional period and the long-term rate in the calculator to see the blended return over your actual time horizon.
Online Banks vs. Credit Unions
Online-only banks consistently offer the highest MMA rates because they have lower overhead — no branch network to maintain. Credit unions, which are member-owned nonprofits, also frequently offer competitive rates and sometimes superior customer service. The main trade-offs are that online banks may have limited ATM access and that credit union membership often requires eligibility (employment, geography, or other criteria).
Strategies to Maximize Your MMA Growth
Automate Monthly Contributions
The single most effective strategy is consistent monthly deposits. Compounding works on whatever balance you have — the more you add, the more the interest has to grow. Even $200 per month added to a $10,000 starting balance at 4.5% APY over 10 years produces $42,000 more than making no contributions at all. Set up automatic transfers from your checking account on payday so the decision is made once and executed automatically.
Use Rate Comparisons Regularly
MMA rates are variable — they move with the federal funds rate. When the Fed raises rates, competitive MMA APYs tend to rise; when the Fed cuts, they fall. It's worth checking your APY against competitors every six to twelve months. If better rates are available elsewhere and you can move your balance without triggering a fee, the switch is often worth the fifteen minutes it takes to open a new account.
Keep Your Emergency Fund Here, Not in Checking
Most financial advisors recommend keeping three to six months of expenses in an emergency fund. If that fund is sitting in a checking account earning 0%, you're losing ground to inflation every year. Moving it to a money market account earning 4%+ means your safety net is also quietly growing. A $25,000 emergency fund in an MMA at 4.5% APY earns over $1,100 in the first year — essentially a bonus for doing nothing differently.
Ladder CDs Above Your Emergency Reserve
For savings beyond your emergency fund that you won't need for a year or more, consider a CD ladder: divide the money across CDs with staggered maturities (6 months, 1 year, 2 years). Keep the liquid portion in your MMA. As each CD matures, roll it into a new CD or move it to the MMA if you need access. This captures the higher CD rates for patient money while maintaining liquidity with the MMA.
Frequently Asked Questions
Yes — money market accounts at FDIC-member banks are among the safest places to keep money. The FDIC insures up to $250,000 per depositor per institution per ownership category. If your bank fails (a rare event), the federal government guarantees your deposits up to that limit. No depositor has lost a single cent of FDIC-insured deposits in the history of the program. For credit unions, the NCUA provides equivalent protection.
APY (Annual Percentage Yield) includes the effect of compounding — it's the actual return you'll earn over a full year if you leave the balance untouched. APR (Annual Percentage Rate) is the base interest rate before compounding is applied. For money market accounts, banks are required by law to advertise APY, so that's the number to use for comparisons. Our calculator uses APY as the input, which is what you'll find on any bank's product page.
Most money market accounts at US banks compound interest daily and credit it to your account monthly. A few compound and credit monthly. The practical difference between daily and monthly compounding is very small — on a $10,000 balance at 4.5% APY, it's less than $2 per year. Because banks advertise APY (which already bakes in compounding), two accounts with the same APY will produce the same annual result regardless of how frequently they compound internally.
Yes — money market account rates are variable and can change at any time, usually without advance notice. Banks typically adjust MMA rates in response to changes in the federal funds rate set by the Federal Reserve. During rate-hiking cycles, MMA rates rise; during cutting cycles, they fall. This is different from a CD, which locks in a rate for the full term. Our calculator assumes a fixed APY throughout the projection period — for long time horizons, the actual result will vary depending on how rates move.
Historically, Regulation D limited savings and money market accounts to six "convenient" withdrawals per month (transfers, checks, debit transactions). The Federal Reserve suspended this rule in April 2020, so the six-transaction limit is no longer federally mandated. However, many banks still enforce their own limits and may charge fees or convert your account to a checking account if you exceed them. Check your specific bank's policy — some still cap transactions at six per month while others have removed the limit entirely.
Yes. Interest earned on a money market account is taxable as ordinary income at both the federal and state level. Your bank will send a Form 1099-INT if you earn $10 or more in interest during the year. You report this income on your tax return for the year it was credited — not when you withdraw it. The after-tax earnings field in our calculator shows you the interest you actually keep after applying your marginal tax rate. At a 22% federal rate, you keep 78 cents of every dollar in gross interest earned.
Consequences vary by bank. Most commonly, the account either earns a substantially lower interest rate for that month or incurs a monthly maintenance fee (typically $5–$15). Some banks convert the account to a regular savings account with a lower rate. A few banks close the account if the balance stays below minimum for multiple consecutive months. The fee field in our calculator lets you model the impact of these charges — even a modest $10/month fee reduces a 4.5% effective yield meaningfully over several years.
Very accurate for planning purposes, with one important caveat: the calculator assumes your APY stays constant throughout the projection period. In reality, money market rates are variable and will change with market conditions — especially over multi-year horizons. For short projections (1–2 years), the results are quite reliable. For 10–30 year projections, treat the output as a directional estimate rather than a precise forecast. The inflation adjustment field helps ground the long-term projections in more realistic terms.
In 2026, the rate gap between competitive MMAs and the best high-yield savings accounts has largely closed — both frequently offer 4.0–5.0% APY. The main reasons to choose an MMA over an HYSA are: you want check-writing access, your bank's MMA offers a higher tier rate for your balance level, or the specific MMA has other features your HYSA lacks. If rates are equal and you don't need check writing, the HYSA with the lower (or no) minimum balance requirement is often the simpler choice. Use the Bank Comparison mode in this calculator to see the dollar difference for your exact deposit amount.
This calculator is for educational and planning purposes only. It does not constitute financial or investment advice. APY projections assume a fixed rate throughout the period; actual MMA rates are variable. FDIC insurance covers deposits up to $250,000 per depositor per institution per ownership category. Tax estimates are simplified; consult a tax professional for your specific situation. No personal data is collected or stored. ✦ CatchyTools.com