1
Enter the starting balance
Add the amount already saved or invested before future contributions and interest begin.
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Savings growth calculator
Free Compound Interest Calculator
A compound interest calculator estimates how a starting balance, recurring contributions, interest rate, time horizon, and compounding frequency can grow into a future balance.
Use it to compare savings goals, understand how much of the final balance comes from interest, and sanity-check long-term growth before committing money to an account or plan.
6 inputs
Balance, contributions, rate, and time
Flexible
Monthly, quarterly, annual, or daily compounding
$0
Free, private, and no signup required
Calculator
Growth inputs
Result
Your balance could grow to $97,246.
This estimate separates what you put in from what compounding adds, using your selected rate, schedule, and contribution timing.
Final balance
$97,246
Projected ending value after all interest and contributions.
Interest earned
$42,246
43.44% of the final balance
Total put in
$55,000
$45,000 from recurring contributions
Effective annual rate
6.17%
APR adjusted for the selected compounding frequency.
Balance by year
Each bar shows the projected balance at the end of the year.
Year 8$46,849
Year 9$52,822
Year 10$59,164
Year 11$65,897
Year 12$73,045
Year 13$80,634
Year 14$88,691
Year 15$97,246
What compounding is doing
The model compounds your balance at the selected frequency, then adds contributions according to your schedule and timing choice.
Your projected balance averages $540 per month across the full time horizon, but growth is usually faster in later years because interest earns interest.
YearBalanceContributionsInterest
0$10,300$250$50
1$13,701$3,000$701
2$17,630$6,000$1,630
3$21,801$9,000$2,801
4$26,229$12,000$4,229
5$30,931$15,000$5,931
6$35,923$18,000$7,923
7$41,222$21,000$10,222
8$46,849$24,000$12,849
9$52,822$27,000$15,822
2
Add recurring contributions
Enter the amount you expect to add and how often you will make that contribution.
3
Set rate and time
Use the annual interest rate or expected return, then choose how many years the balance will grow.
4
Choose compounding
Select the frequency from your account terms to estimate final balance, contributions, and interest earned.
FAQ
Compound interest questions
What is a compound interest calculator?
A compound interest calculator estimates how money can grow when interest is added back to the balance and earns more interest over time.
How is compound interest different from simple interest?
Simple interest applies only to the original principal. Compound interest applies to both the principal and previously earned interest.
How often should interest compound?
Use the frequency from the account or loan terms. Common options are monthly, quarterly, daily, or annually.
Do recurring contributions compound too?
Yes. Once a contribution is added to the balance, it can earn future interest according to the selected compounding schedule.
Can this calculator be used for loans?
It is best for savings and investment growth scenarios. For amortizing loans with regular repayment, use a dedicated loan repayment calculator.