Investment Tools
Interest Calculator
Calculate how much interest you'll earn or owe on any amount. Compare simple vs compound interest and see how compounding frequency affects your returns.
Configure
Interest parameters
Interest type
Compounding frequency
Breakdown
Balance composition
How interest is calculated
01
Choose interest type
Select simple interest (on principal only) or compound interest (on principal plus accumulated interest).
02
Enter amount & rate
Input your principal, annual interest rate, and time period in years.
03
See your results
Get total interest earned, ending balance, and the effective annual rate for compound interest.
Frequently asked questions
Simple interest formula ▼
Simple interest = Principal × Rate × Time. For $10,000 at 5% for 3 years: $10,000 × 0.05 × 3 = $1,500 in interest.
Compound interest formula ▼
Compound interest: A = P(1 + r/n)^(nt), where P is principal, r is annual rate, n is compounding periods per year, and t is years. This grows exponentially because interest earns interest.
What is the effective annual rate (EAR)? ▼
The EAR converts a nominal rate compounded multiple times per year into an equivalent annual rate. Monthly compounding at 6% nominal = 6.168% effective. This lets you compare rates fairly.
Disclaimer: Results are for informational purposes. Actual bank savings or loan rates may vary. Read the full terms before opening any account or taking a loan.
Support NumeraFin
Use this result, then keep moving to the next tool
If this calculator helped, share it, leave a quick rating, or jump back into the directory for the next decision.
Was this helpful?
Rate this tool
Tap a star to leave a rating.