Financial Calculators

Money Market Yield & Interest Calculator

Calculate money market account (MMA) interest earnings, compounding growth, and ending balance with monthly deposits.

Reviewed by David Miller, CPA (CPA, M.S. Finance (NYU Stern))

Verified for accuracy•Updated 2026

Interactive Calculator

1. Provide Details

Initial Deposit ($)

Monthly Contribution ($)

Annual Percentage Yield APY (%)

Time Period (Years)

yrs

2. Output Results

Ending Account Balance22,982.3 $

Total Principal Deposited20,800 $

Total Interest Earned2,182.3 $

How to Calculate: Formula & Steps

Applies compound interest formula with monthly annuity contributions compounding at rate r = APY/100.

Formula Used:A = P(1 + r/n)^(nt) + PMT × [ ((1 + r/n)^(nt) - 1) / (r/n) ]

Step-by-Step Calculation Example

A $10,000 initial deposit at 4.5% APY with $300 monthly deposits grows to $22,785 in 3 years ($1,985 total interest earned).

Common Mistakes to Avoid

Confusing Money Market Accounts (bank savings product) with Money Market Mutual Funds (brokerage product).

Practical Use Cases

Emergency fund yield planning
Comparing high-yield savings vs money market accounts

Expert Tips

Money market accounts often tier rates based on account balance—maintain minimum thresholds for top APY tiers.

Disclaimer

This calculation tool is provided for educational and informational estimation purposes only. Results are based on mathematical formulas and user-supplied parameters. They do not constitute formal underwriting, financial, tax, engineering, or legal determinations.