Compound Interest Calculator – Amount, Interest, Rate & Time
Use this Compound Interest Calculator to quickly find maturity amount, interest earned, principal, rate, or time for different compounding options like yearly, monthly, or daily.
Choose Mode & Enter Values
Pick a mode, then fill the fields below.Result
Results are rounded to 2 decimals. Effective annual rate (EAR) is also shown for the selected compounding.
Formulas Used
- Amount: A = P × (1 + r/n)n×t
- Interest: I = A − P
- Principal: P = A ÷ (1 + r/n)n×t
- Rate: r = n × [(A/P)1/(n×t) − 1]
- Time: t = ln(A/P) ÷ [n × ln(1 + r/n)]
- EAR: (1 + r/n)n − 1
FAQs
Is the rate nominal or effective?
Enter the nominal annual rate (for example, 8% per year). The calculator shows the effective annual rate (EAR) based on your compounding choice.
Does it support daily or custom compounding?
Yes. Choose Daily (365) for daily compounding. For weekly, bi-weekly, or any custom schedule, select Custom and enter the value of n.
Why might my result differ from bank figures?
Banks may use different day-count conventions, extra fees, or rounding rules. This tool uses a clean mathematical formula with the compounding you select.
Where Can You Use This Compound Interest Calculator?
You can use this Compound Interest Calculator in many real-life money situations where growth over time matters. Here are some common ways it can help you plan and compare options.
Bank Fixed Deposits & Savings Plans
Estimate how much your fixed deposits, recurring deposits, or high-interest savings accounts can grow with different interest rates and tenures.
SIP, Mutual Funds & Investment Growth
Check how your lump-sum or periodic investments may grow using compound interest assumptions before choosing a scheme or target amount.
Retirement Corpus & Long-Term Planning
Plan how much you should invest today to reach a retirement corpus or future fund for long-term goals like buying a house or starting a business.
Children’s Education & Marriage Fund
Estimate how much your savings for children’s higher education or marriage can grow when interest is compounded monthly or yearly.
Compare Different Banks & Schemes
Compare two interest rates, compounding frequencies, or time periods to see which bank deposit or investment scheme gives better returns.
Business Funds & Reinvestment
Use compound interest to estimate how reinvesting profits or keeping money in interest-earning accounts can help grow business funds over time.
Compound Interest Calculator – FAQ
It uses the standard compound interest formula to calculate amount, interest, principal, rate, or time based on your inputs and chosen compounding frequency.
The main formula is A = P × (1 + r/n)n×t where P is principal, r is annual rate, n is compounding periods per year, t is time in years, and A is the final amount. Interest I = A − P.
EAR is the true yearly growth from compounding: EAR = (1 + r/n)n − 1. The calculator shows EAR for the compounding frequency you select.
Yes. You can switch the time unit to months and the tool will convert months to years internally by dividing the value by 12.
Select how often interest is added to your balance: yearly (1), half-yearly (2), quarterly (4), monthly (12), daily (365), or a custom value like weekly (52). More frequent compounding usually means slightly higher returns.
Banks may use different day-count rules, fees, or rounding. This Compound Interest Calculator uses a clean mathematical formula with fixed compounding periods for clarity.
