Compound Interest Calculator for Retirement Planning

To use our compound interest calculator, enter your starting principal (the amount you're investing today), your expected annual interest rate, the number of years you'll invest, and how frequently interest compounds. Then click "Calculate" to see your projected final balance.

The compound interest formula is: A = P × (1 + r/n)^n×t, where P is principal, r is the annual rate as a decimal, n is compounding periods per year, and t is time in years.

for Retirement Planning examples:

• Baseline: Start small and let compounding do the heavy lifting.
• With monthly deposits: Compare the impact of consistent contributions.
• Higher return case: Evaluate upside while understanding risk tradeoffs.

The key takeaway: starting early makes an enormous difference. An investor who starts at 25 versus one who starts at 35 can accumulate double the wealth by retirement, even if they invest identical amounts.