Free Online Savings Account Growth Calculator
Wondering how much your savings will be worth in 5 or 10 years? Our free calculator shows interest earned, total balance & a visual breakdown — updated as you type.
Total Savings Breakdown
Your Total Savings
Frequently Asked Questions
See exactly how your savings grow with compound interest. Adjust APY, time period & monthly contributions in real time. Free calculator — results update instantly.
This calculator uses the monthly compound interest formula to project your savings balance over time. You enter four inputs:
- Initial Deposit — the lump sum you start with
- Monthly Contribution — how much you add every month
- Time Period — in months or years
- APY (Annual Percentage Yield) — your account’s annual interest rate, including the effect of compounding
Each month, your running balance earns interest at a rate of APY ÷ 12. That interest is added back to your balance, so the following month you earn interest on a slightly larger amount. This “interest on interest” effect is what makes compound growth exponential rather than linear.
Formula used:
A = P × (1 + r)^n + PMT × [(1 + r)^n − 1] / r
Where P = initial deposit, r = monthly rate (APY / 12), n = total months, PMT = monthly contribution.
APY (Annual Percentage Yield) reflects the real yearly return after compounding is factored in. APR (Annual Percentage Rate) is the stated rate before compounding.
For example, a savings account with a 5% APR compounded monthly actually yields a 5.12% APY. When comparing savings accounts, always use APY — it is the true apples-to-apples number. Most U.S. bank disclosures are required by law (the Truth in Savings Act) to display APY, so you can plug the APY directly into this calculator without any conversion.
The calculator gives a mathematically precise projection based on the inputs you provide. In practice, results may differ because:
- APY is variable on most savings accounts — banks can change it at any time
- Contributions may vary — you might skip a month or add a bonus deposit
- Tax is not included — interest income is typically taxable; your after-tax return will be lower
- Inflation is not modeled — $39,000 in 10 years has less purchasing power than $39,000 today
Use the results as a planning benchmark, not a guarantee. For personalized projections, consult a licensed financial advisor.
Interest rates fluctuate with Federal Reserve policy. As of early 2026, after three Fed rate cuts in late 2025:
| Account Type | Typical APY Range |
|---|---|
| Traditional bank savings | 0.01%–0.10% |
| Online high-yield savings (HYSA) | 3.50%–4.80% |
| Money market accounts | 3.00%–4.50% |
| 12-month CD | 3.80%–5.00% |
The national average for standard savings accounts remains around 0.40%–0.60%. If your goal is to maximize compound growth, high-yield savings accounts at online banks typically offer the most competitive rates with no minimum balance requirement.
Disclaimer: Rates change frequently. Always verify current APY directly with your financial institution before making decisions.
Yes — significantly. Regular monthly contributions amplify compounding because each deposit immediately starts earning its own interest.
Example (APY = 4%, 10 years):
| Strategy | Balance After 10 Years |
|---|---|
| $10,000 lump sum, no contributions | $14,918 |
| $10,000 + $200/month | ~$39,800 |
| $0 initial + $300/month | ~$44,000 |
Monthly contributions also enforce a savings discipline that a one-time deposit does not. Even small consistent amounts — $50 or $100 per month — create meaningful differences over multi-year horizons due to compounding.
Simple interest is calculated only on your original principal. If you deposit $10,000 at 5% simple interest for 10 years, you earn $500/year — always the same amount — totaling $5,000 in interest.
Compound interest calculates interest on your principal plus all previously earned interest. That same $10,000 at 5% compounded monthly grows to approximately $16,470 — earning $6,470 in interest, or 29% more than simple interest over the same period.
For savings accounts and most deposit products, interest is always compound. Simple interest is more commonly seen in short-term personal loans or certain bonds.
Work backwards from your target:
- Set your goal amount (e.g., $50,000 for a house down payment)
- Fix your time horizon (e.g., 5 years)
- Enter your expected APY (research current HYSA rates)
- Adjust the monthly contribution until the “Your Total Savings” figure reaches your target
- Note the required monthly contribution and check it against your budget
If the required monthly amount exceeds your budget, either extend the time horizon or increase your initial deposit. Running multiple scenarios in the calculator takes less than a minute and immediately reveals which lever has the biggest impact on your outcome.
Yes. Enter the CD’s APY and its term (in months or years). Set monthly contribution to $0 if it is a standard CD that does not accept additional deposits after opening. Set the contribution amount if you have an add-on CD that allows periodic deposits.
Note that CDs lock in the APY for the full term, unlike savings accounts where APY is variable — so CD projections are generally more predictable.
The toggle converts your input: selecting 10 Years is identical to entering 120 Months. The calculator always runs on months internally to ensure monthly compounding accuracy. If results seem unchanged, verify that the number itself converted — e.g., switching from “10 Years” to “Months” should display 120, not 10.
Yes — completely free, no account required, no personal data collected. The calculator runs entirely in your browser using JavaScript; no information you enter is transmitted to any server. It is designed for quick, private financial planning estimates with zero friction.