Finance & Investment · Interest
Compound Interest Rate Calculator
Work out the annual interest rate needed — or the rate you actually earned — when a starting amount grows to a final amount over a period, compounded annually, quarterly, monthly, weekly, daily or continuously. Shows the effective annual rate and the same growth as a rate at every other compounding frequency.
Your inputs
₹ 1 lakh
₹ 2 lakh
Your result Live
Annual Interest Rate
6.9919%
compounded quarterly: ₹1,00,000 grows to ₹2,00,000 in 10 years
- Effective Annual Rate
- 7.1773%
- Rate per quarter
- 1.74797%
- Total Interest Earned
- ₹1,00,000
- Growth Multiple
- 2.000×
- Total Growth
- 100.00%
- Principal · 50%₹1,00,000
- Interest · 50%₹1,00,000
Year-by-year growth
10 rowsThe same growth at every compounding frequency
8 rowsAn estimate from the assumptions you entered, not a guaranteed outcome.
How this is calculated
r = n × ((A ÷ P)^(1 ÷ (n × t)) − 1) · continuous: r = ln(A ÷ P) ÷ t
- r
- Annual (nominal) interest rate, as a decimal
- A
- Final amount
- P
- Principal (starting amount)
- n
- Compounding periods per year
- t
- Time in years
This is the Compound Interest Calculator run backwards: you know where the money started, where it ended up and how long it took, and want the rate. The quoted (nominal) rate depends on how often interest compounds — the same growth needs 8 % compounded annually but only 7.70 % compounded continuously — so the effective annual rate, which doesn't depend on frequency, is the fair way to compare. Use it to check what a deposit really paid, or what return a goal demands.
Assumptions & sources
- Nothing is added or withdrawn during the period; for regular deposits use the TVM Calculator.
- The rate is constant, and the same growth is assumed to come from the compounding frequency you pick.
- Tax on the interest is not deducted.
- 1Investments (Bodie, Kane & Marcus), chapters on returns, compounding and the time value of money — McGraw-Hill
- 2CFA Program Curriculum — Quantitative Methods: The Time Value of Money — CFA Institute
Calculator ID FIN-INT-CIR-001 · version 1.0.0
Common questions
How do I calculate the interest rate from a starting and a final amount?
Divide the final amount by the principal, raise it to the power 1 ÷ (n × t), subtract 1 and multiply by n. ₹1,00,000 growing to ₹2,00,000 in 10 years compounded quarterly needs 6.99 % a year; compounded annually it needs 7.18 %, and continuously 6.93 %.
What is the difference between the nominal and the effective rate?
The nominal rate is the quoted rate before compounding; the effective annual rate is what the money really grows by in a year. Banks quote nominal rates, so compare deposits by their effective rate.
Is this the same as CAGR?
The effective annual rate here equals CAGR — the steady yearly growth between the two amounts. The nominal rate additionally depends on the compounding frequency.