Interest Rate Calculator
Multi-purpose interest calculator for simple, compound, rate, and time calculations.
Interest Rate Calculator
Calculate simple interest, compound interest, find interest rate, or determine time period for your investments
$
Final Amount (Simple Interest)
$140,000
After 5 years at 8% p.a.
Principal Amount
$100,000
Starting investment
Interest Earned
$40,000
Interest component
Final Amount
$140,000
Total value
Investment Growth
Year-by-Year Interest
Calculation Details
Principal:$100,000
Interest Rate:8% p.a.
Time Period:5 years
Simple Interest:$40,000
Interest Earned:$40,000
Final Value:$140,000
Growth Multiple:1.40x
Return Percentage:40.00%
Formulas Used
SI = P × r × t
Amount = P + SI
Amount = P + SI
P = Principal amount, r = Interest rate (as decimal)
t = Time in years, A = Final amount, n = Compounding frequency