Compound Interest Calculator
Enter your principal, annual interest rate, time period, and how often interest compounds to calculate compound interest — interest earned on both your original principal and previously earned interest.
Save your student profile to track computations, past questions & GPA targets.
Enter principal, rate, and time to see the result.
How It Works
Compound interest is calculated on the principal plus all interest already earned, so it grows faster than simple interest over time. The formula is: A = P × (1 + r/n)^(n×t), where P is the principal, r is the annual interest rate as a decimal (rate % ÷ 100), n is the number of times interest compounds per year, and t is the time in years. A is the final amount after compounding, and the interest earned is Interest = A − P.
MyDelsu is an independent student platform and is not affiliated with DELSU administration. This tool is provided for guidance only — always verify results against your official transcript, result slip, or academic regulations.
Frequently Asked Questions
What does compounding frequency mean?+
It's how many times per year your interest is calculated and added back to the principal: Annually = once a year (n=1), Semi-Annually = twice a year (n=2), Quarterly = four times a year (n=4), and Monthly = twelve times a year (n=12). The more frequently interest compounds, the faster your balance grows for the same annual rate.
Why does compound interest earn more than simple interest at the same rate?+
Because compound interest is calculated on your growing balance (principal + interest already earned), not just the original principal — so each period's interest is calculated on a slightly larger amount than the period before.
Which compounding frequency should I choose?+
Use whatever frequency matches your actual savings account, investment, or loan terms — check your bank or provider's documentation. If you're not sure, Annually is the most common default for illustrative calculations.
How much difference does compounding frequency actually make?+
For most everyday rates and time periods, the difference between quarterly and monthly compounding is fairly small — the bigger factor is always the interest rate and how long the money compounds for. Try switching frequencies above to see the exact difference for your numbers.
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