Finance calculators

Money Market Calculator

Updated Aug 13, 2026 By Jehan Wadia
Rate Formulas
What would you like to calculate?
Each mode shows only the inputs it needs. All fields stay editable at all times.

Scenario A

Scenario A inputs
% per year
Timeframe
Years
Months
Years 0–99, months 0–11. At least 1 month total.
Growth Over Time — Scenario A
Step-by-Step Solution

Introduction

A money market account is a savings account that usually pays a higher interest rate than a basic one. This money market calculator shows how much your money can grow over time.

Pick what you want to find out. You can solve for your total savings, the monthly deposit you need to hit a goal, or the time it takes to get there. Just type in your starting balance, your monthly deposit, your APY, and how often interest compounds.

You will see your ending balance, your total deposits, and the interest you earn. A chart and a data table show your growth month by month. You can also compare two accounts side by side to see which rate saves you more. Each answer comes with the math steps, so you can check the work yourself.

How to use our Money Market Calculator

Enter your savings details below and the calculator shows your total savings, the monthly deposit you need, or how long it will take to hit your goal, plus your total interest earned.

What would you like to calculate? Pick one of three modes: Total Savings, Monthly Contribution Needed, or Timeframe Needed. The calculator only shows the fields that mode needs.

Starting Balance: Type the money you already have in your money market account today. Use $0.00 if you are starting from scratch.

Monthly Contribution: Type the amount you plan to add each month. This field is hidden when you ask the calculator to find that amount for you.

Savings Goal: Type the balance you want to reach. This field shows up in the Monthly Contribution and Timeframe modes. To plan a target date around a set dollar amount, our savings goal calculator works well alongside this one.

APY: Type the annual percentage yield your bank pays, like 4.5. This is the yearly rate your money earns. If your bank quotes a plain interest rate instead, the APY to APR calculator can help you translate between the two.

Compounding Frequency: Choose how often interest is added to your balance: daily, monthly, quarterly, or annually. For a closer look at day-by-day growth, try the daily compound interest calculator.

Timeframe: Enter how long you will save, in years and months. Years can be 0 to 99 and months 0 to 11, with at least 1 month total.

Calculate, Reset, and Compare: Click Calculate to see your results, chart, and step-by-step math. Click Reset to start over. Click Compare a Second Scenario to test two rates or plans side by side.

What Is a Money Market Account?

A money market account (MMA) is a savings account at a bank or credit union. It pays interest on the money you keep in it, and it usually pays more than a basic savings account. Many money market accounts also come with a debit card or checks, so you can reach your cash when you need it.

How Money Market Accounts Grow Your Money

Your bank pays you interest for keeping your money there. That interest gets added to your balance. Then the new, bigger balance earns interest too. This is called compound interest. The longer you leave your money alone, the more it grows.

Money market savings grow from three things:

  • Your starting balance — the money you already have saved.
  • Your monthly deposits — the money you add each month.
  • Interest earned — the money the bank pays you. You can check a single month's payout with the monthly interest calculator.

What APY Means

APY stands for Annual Percentage Yield. It shows how much your money grows in one year, including compounding. A 4.50% APY means $1,000 turns into about $1,045 after a year if you don't touch it. When you shop for an account, compare the APY, not just the interest rate. The higher the APY, the faster your savings grow. Our savings interest calculator shows the same idea from the interest side.

Compounding Frequency

Banks add interest to your account on a schedule — daily, monthly, quarterly, or yearly. Adding it more often helps a little, because your interest starts earning interest sooner. The difference is small, but over many years it adds up. The effective interest rate calculator shows exactly how much frequency changes your yield.

Money Market vs. Savings vs. CDs

A regular savings account is simple and easy to open, but often pays less. A CD (certificate of deposit) locks your money up for a set time and may pay more, but you pay a fee if you take it out early. A money market account sits in the middle: strong rates with easy access to your cash. A high-yield savings account is another close cousin worth comparing.

Things to Watch For

  • Minimum balance: Some accounts need $1,000 or more to avoid a fee or earn the best rate.
  • Monthly fees: A fee can eat up the interest you earn.
  • Withdrawal limits: Some banks limit how many transfers you can make each month.
  • Changing rates: The APY can go up or down. It is not locked in like a CD.
  • Insurance: Look for FDIC (bank) or NCUA (credit union) coverage, which protects up to $250,000 per depositor.
  • Inflation: Rising prices chip away at what your balance can buy — see the inflation calculator.

Good Uses for a Money Market Account

Money market accounts work well for an emergency fund, a house down payment, a car, a wedding, or any goal in the next few years. They are safe and steady. For long-term goals like retirement, investing usually earns more, but it also carries more risk. Parents saving for tuition may also want the college savings calculator.

Tips to Save Faster

  • Set up an automatic transfer each payday so you never forget. A monthly budget calculator helps you find room for it.
  • Start early. Time matters more than the size of each deposit — the rule of 72 calculator shows how fast money doubles.
  • Compare banks once a year. Online banks often pay higher APYs.
  • Leave the interest in the account so it can compound, and check your projected balance with the future value calculator.
  • Remember that interest you earn counts as taxable income, so factor it into your income tax planning.

Formulas used

Monthly growth factor from APY
f = (1 + \text{APY})^{1/12}
Total months in timeframe
m = 12Y + M
Future value (total savings)
FV = B_0 f^{m} + C \cdot \frac{f^{m} - 1}{f - 1}
Required monthly contribution
C = \frac{G - B_0 f^{m}}{\dfrac{f^{m} - 1}{f - 1}}
Months needed to reach goal
m = \frac{\ln\!\left(\dfrac{G + k}{B_0 + k}\right)}{\ln f}, \quad k = \frac{C}{f - 1}
Months needed at 0% APY
m = \frac{G - B_0}{C}
Total contributions and total interest
\text{Contributions} = C \times m, \quad \text{Interest} = FV - B_0 - C \times m
Monthly balance recursion
B_k = B_{k-1} f + C

Frequently asked questions

When does the calculator add my monthly deposit?

At the end of each month. The tool first adds that month's interest to your balance, then drops in your deposit. So your newest deposit does not earn interest until the next month.

If you deposit at the start of the month instead, your real balance will be a little higher than the estimate.

Should I type my bank's APY or its interest rate?

Type the APY. That is the number banks show in big print on money market accounts, like 4.50%.

APY already includes compounding, so it gives the most accurate result. If your bank only lists a plain rate, convert it first, then enter the APY here.

Why don't my results change when I switch the compounding frequency?

Because APY already has compounding baked into it. A 4.50% APY earns 4.50% in a year whether the bank pays interest daily or yearly.

The dropdown simply records how your bank credits interest, and it shows up in your results summary and chart notes.

Why is my required monthly deposit $0.00?

Your starting balance grows enough on its own to pass your goal in the time you picked. The calculator shows a note telling you this.

To see a real deposit amount, lower your timeframe, raise your goal, or lower your starting balance.

Why does the timeframe answer round up to a whole month?

Banks pay interest in full periods, and most people deposit once a month. So the tool rounds up to the next whole month.

That means your balance at the end may be a bit above your goal. The step-by-step section shows the exact unrounded number of months.

Can I use $0 as my starting balance?

Yes. Enter $0.00 if you have not saved anything yet. The calculator will grow your monthly deposits only.

Starting balance cannot be a negative number.

What does the message about not reaching my goal mean?

It means your money never gets there with those numbers. This happens when your APY is 0% and your monthly deposit is $0.00, or when it would take more than 100 years.

Fix it by raising your monthly deposit, your APY, or your starting balance.

Does this money market calculator include taxes?

No. It shows interest before taxes. The interest you earn usually counts as taxable income, so your take-home total will be lower.

To estimate after-tax growth, try entering a slightly lower APY.

Does it include bank fees or minimum balance rules?

No. Monthly fees, minimum balance penalties, and rate tiers are not part of the math.

If your bank charges $5 a month, subtract that from your monthly deposit before you enter it.

What do the three colors on the chart mean?

The chart stacks your balance in three parts:

  • Purple — your starting balance
  • Green — the deposits you added
  • Orange — the interest you earned

Stacked together, they equal your total balance at that point in time.

Why does the data table skip some months?

To keep it easy to read. Short plans show every month. Longer plans show every 3, 6, or 12 months, plus the final period.

Click Show data table under the chart to open it.

Is my starting balance part of "Total Contributions"?

No. Total Contributions only counts the monthly deposits you make. Your starting balance is listed on its own line.

Add the two together plus interest and you get your total savings.

How do I compare two banks or two rates?

Click Compare a Second Scenario. A second card opens with its own inputs.

Type one bank's APY in Scenario A and the other in Scenario B. A comparison table then shows the dollar difference in interest, deposits, and your ending balance.

Can I add weekly or biweekly deposits?

The tool uses monthly deposits only. To match a weekly plan, multiply your weekly amount by 52, then divide by 12.

Example: $50 a week is about $216.67 a month.

Can I plan for withdrawals from the account?

No. Deposits must be $0.00 or more, so you cannot enter a negative amount.

If you plan to pull money out, lower your monthly deposit to your true net savings each month.

Why is my interest smaller than APY times my total deposits?

Because your deposits arrive over time. Money you add in the last month only earns interest for a few weeks, not a full year.

Only your starting balance earns interest the whole time.

What is the longest timeframe I can use?

Up to 99 years and 11 months. You must enter at least 1 month total.

In Timeframe mode, results over 100 years show a warning instead of an answer.

Does the calculator adjust for inflation?

No. Every dollar shown is in today's dollars, with no price changes applied.

Your future balance will buy less than the same amount buys now, so treat the result as a plain dollar total.

My bank's APY can change. How do I plan for that?

Money market rates move up and down, so treat your result as an estimate.

Use the compare feature to test a high rate and a low rate. That shows your best and worst case side by side.

Why do the step-by-step numbers look slightly different from my results?

The steps show rounded numbers so the math is easy to follow. The calculator itself uses full decimals.

Small penny gaps are normal and do not change your answer in a meaningful way.