Interest Rate Solver
Solve for payment, rate, principal, or time using flexible interest formulas and comparison charts.
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