Savings Calculator
Calculate compound interest growth over time with optional initial deposits and recurring monthly contributions.
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This savings calculator estimates the long-term growth of your money based on your starting deposit, recurring monthly additions, an estimated annual interest rate, and a timeframe in years. The calculation compounds growth in monthly increments, applying the monthly portion of your annual rate and adding your chosen monthly deposit at each step. All inputs are optional: leaving a field empty uses default baseline numbers, including a zero starting balance, zero monthly deposit, a five percent annual rate, and a ten-year duration. If you enter negative numbers for balances or rates, the tool automatically adjusts them to zero before calculating. Any entered duration is rounded to a whole number of years and set to a minimum of one year. Once calculated, the tool displays an annual breakdown showing total accumulated deposits, earned interest, and ending balances rounded to two decimal places for each year of your savings plan.
Instructions
- Enter your initial starting deposit amount, or leave it at zero if starting from scratch.
- Specify an ongoing monthly contribution amount that you plan to add each month.
- Enter the expected annual interest rate as a percentage.
- Set the projection timeline in years.
- Review the annual breakdown table to see total balances, accumulated deposits, and interest earned over time.
Examples
- Starting with an initial balance of $1,000, adding $200 each month at a 5% interest rate over 10 years.
- Starting from $0 and contributing $500 monthly at a 4.5% annual rate over a 15-year horizon.
FAQ
How frequently is interest calculated and added?
Interest is compounded monthly, applying one twelfth of the annual interest rate to the balance alongside your monthly contribution in each step.
What happens if I leave an input field blank?
Blank inputs use default baseline values: 0 for the initial balance, 0 for monthly contributions, 5% for the interest rate, and 10 years for the timeline.
Can I enter a timeline shorter than one year or fractional years?
Timelines are converted to integer years, and any value less than one year is automatically adjusted to a minimum of one full year.
What happens if I enter a negative value?
Negative initial deposits, negative monthly contributions, and negative interest rates are automatically replaced with zero before the projection runs.