Savings Calculator
Project how your savings balance grows with a starting amount, monthly contributions and an interest rate.
How this calculator works
- Enter your starting balance.
- Enter how much you plan to contribute each month.
- Enter an annual interest rate (use a savings account APY, or a conservative long-term estimate for investments).
- Enter the number of years to project, and see your total contributions, interest earned and final balance, plus a growth chart.
This calculator projects how a savings balance grows over time when you start with a lump sum, add a fixed amount every month, and earn interest that compounds monthly. It's the same math behind high-yield savings accounts, CDs with monthly compounding, and simple long-term investment projections.
Example
Starting with $1,000, contributing $200/month at 4% annual interest for 10 years grows to roughly $30,000 — about $25,000 of that from your own contributions and $5,000 from interest.
Limitations
Interest is modeled as a fixed annual rate compounding monthly, which won't exactly match variable-rate accounts or investments with fluctuating returns. This is a planning estimate, not a guarantee — real returns vary.
Frequently asked questions
How does compound interest work?
Compound interest means you earn interest on your interest, not just your original balance. Each month, interest is calculated on your current balance (starting balance + contributions + interest already earned), so growth accelerates over time.
How much should I save each month?
That depends on your goals and timeline — try the Savings Goal Calculator if you have a specific target amount and date in mind.
Can I include an existing balance?
Yes, the “starting balance” field is exactly for that — any amount you already have saved.
What interest rate should I use?
Use your actual account's APY if you have one. For a rough long-term estimate, many planners use a conservative single-digit percentage, but the right number depends on where the money is held.