Compound Interest Calculator – Calculate CI Online

Principal Amount

Total intrest

Total Amount


Quick answer

Enter the principal, annual interest rate, time period, and compounding frequency; the tool calculates the final amount and total compound interest earned.

Key facts

  • Uses the standard compound interest formula A = P(1 + r/n)^(nt)|Supports 5 compounding frequencies: weekly, monthly, quarterly, half-yearly, and yearly|Displays both the final amount and the total interest earned|Runs entirely in your browser via JavaScript, no data sent to a server|Free with no usage limit

What is this tool?

This tool calculates how much a principal amount will grow over time when interest compounds at a chosen frequency, showing both the final amount and the total interest earned.

How to use it

Enter your principal, the annual interest rate, the time period in years, and choose how often interest compounds (weekly, monthly, quarterly, half-yearly, or yearly), then click Calculate to see the results.
  1. Enter the principal amount.|Enter the annual interest rate as a percentage.|Enter the time period in years.|Select the compounding interval (weekly, monthly, quarterly, half-yearly, or yearly).|Click Calculate to see the final amount and total interest.

Example

Example: a principal of 10,000 at 8% annual interest compounded yearly for 5 years grows to approximately 14,693.28, earning about 4,693.28 in compound interest.

How it works

A = P(1 + r/n)^(nt), where P is the principal, r is the annual interest rate (as a decimal), n is the number of compounding periods per year (52 for weekly, 12 for monthly, 4 for quarterly, 2 for half-yearly, 1 for yearly), and t is the time in years. Total interest = A - P. This is the standard compound interest formula.

Common use cases

Estimating how a fixed deposit or savings account will grow over time.|Comparing outcomes for different compounding frequencies at the same rate.|Planning long-term savings goals.|Understanding the effect of compounding frequency on returns.

Benefits

Free, instant, and supports multiple compounding frequencies in a single calculator.

Limitations

This calculator assumes a fixed interest rate for the entire period with no withdrawals or additional deposits; real-world accounts may have variable rates, fees, or minimum balance requirements that affect actual returns. Results are for estimation only.

Privacy & your data

All calculations run locally in your browser using JavaScript. Your principal, rate, and time period are not sent to or stored on the A2Z Tools server.

Frequently asked questions

What is the difference between simple and compound interest?

Simple interest is paid only on the principal. Compound interest is paid on the principal plus previously earned interest, so the balance grows faster over time.

Why does compounding frequency matter?
More frequent compounding (e.g. monthly versus yearly) means interest is calculated and added to the principal more often, which slightly increases the final amount for the same nominal annual rate.
How does compounding frequency affect the result?

More frequent compounding (monthly vs yearly) produces a slightly higher final amount at the same nominal rate, because interest starts earning interest sooner.

Does this account for taxes on interest earned?
No. The calculation shows gross compound interest only; taxes on interest income depend on your local tax rules and are not included.
Can I use this for loans as well as savings?

Yes — the same formula describes how a debt grows if unpaid, which makes the calculator useful for understanding loan balances too.

Is this guaranteed to match my bank's calculation exactly?
It uses the standard compound interest formula, but your bank's actual terms, fees, or rounding conventions may cause small differences -- treat results as an estimate.
Is my data stored anywhere?
No. All calculations happen locally in your browser; nothing is sent to or stored on the A2Z Tools server.

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