Savings Calculator with Interest
See how a savings goal grows with monthly contributions and compound interest. Includes a year-by-year breakdown of your balance, total deposits, and interest earned.
What is Savings Calculator with Interest?
The savings calculator shows how a starting deposit plus regular monthly contributions grow with compound interest over time. The earlier you start and the more often interest compounds, the bigger the gap between what you put in and what you end up with.
Use it to model emergency funds, sinking funds for big purchases, or long-term savings goals where the time horizon and rate are roughly known.
Formula
For a starting balance P, monthly deposit m, annual rate r, compounding n times per year, over t years:
Ending balance = P × (1 + r/n)n×t + m × ((1 + r/n)n×t − 1) / (r/n)
The first term is the growth of the starting balance. The second is the future value of an ordinary annuity (the contributions).
Worked example
Start with $1,000, deposit $200/month at 4.5% APY compounded monthly for 10 years:
- Total deposits: $1,000 + ($200 × 12 × 10) = $25,000
- Ending balance: ~$31,924
- Interest earned: $6,924
How to use this calculator
- Enter your starting balance and monthly deposit.
- Enter the APY (high-yield savings accounts are around 4-5% in 2026; check your bank).
- Enter your savings horizon in years.
- Pick how often interest compounds (most online banks compound daily).
Frequently asked questions
APY vs APR — what's the difference?
APR (Annual Percentage Rate) is the simple annual rate. APY (Annual Percentage Yield) accounts for compounding. If a bank advertises 4.5% APY, that's already including compounding effects. APY ≥ APR, with the gap larger the more frequent the compounding.
Where can I get the highest savings interest right now?
High-yield savings accounts (HYSA) at online banks (Marcus, Ally, Discover, etc.) and money market accounts at brokerages (Fidelity, Vanguard) typically pay close to the federal funds rate. As of 2026, these are around 4-5% APY. Check Bankrate or NerdWallet for current rankings; rates change with Fed policy.
Should I save in cash or invest in stocks for long-term goals?
For goals less than 3 years out, cash savings beats stocks because you can't afford a down market when you need the money. For 5+ years, stocks historically outperform — the S&P 500 has averaged ~10% nominal annual returns over many decades versus 4-5% in HYSA. Mix the two based on your timeline.
Are savings interest gains taxable?
Yes, in the U.S. interest from savings accounts is taxed as ordinary income. The bank issues a Form 1099-INT for any year you earn $10+ in interest. State income tax also applies in most states. Tax-advantaged options for long-term savings include Roth IRA (after-tax dollars in, tax-free growth and withdrawal), Traditional IRA, 401(k), and HSA.
What if I deposit more than I planned in some months?
This calculator assumes equal monthly deposits. If you can vary, just rerun the calculation with different parameters. For mixed scenarios, bump the monthly amount to your average and the result will be approximately correct.