Compound Interest Calculator

Compare simple vs compound interest and estimate maturity value for yearly, half-yearly, quarterly, or monthly compounding.

GratuityPPFEPF / PFEMISIPFDNPSIncome TaxHRAAgeGSTPercentageBMITake-Home SalaryStamp DutySIP Step-UpCompound InterestLumpsumLoan EligibilityTDSRDSection 80C PlannerSalary HikeDiscount
How to use this calculator
  1. 1

    Enter principal and tenure

    Add the one-time amount and number of years you want to keep it invested.

  2. 2

    Set interest and mode

    Choose simple or compound interest, then set annual interest rate.

  3. 3

    Pick compounding frequency

    For compound mode, choose yearly, half-yearly, quarterly, or monthly to compare maturity impact.

Rs
%
yrs

Interest projection

Principal investedRs 2,00,000
Interest earnedRs 2,87,038
Compoundingquarterly

Next step

FD calculatorRD calculatorSIP calculatorLumpsum calculator

Formula used: A = P x (1 + r/n)^(n x t). Rates are estimates for planning only.

Quick answer

Compound interest grows faster than simple interest because interest is earned on prior interest. The gap widens as tenure increases.

A compound interest calculator helps you estimate how much your savings or investment can grow when returns are reinvested. Unlike simple interest, where interest is calculated only on principal, compound interest calculates return on principal plus accumulated interest.

What is this calculator?

This tool compares simple and compound interest for Indian savers and investors. You can set principal, annual rate, tenure, and compounding frequency to estimate maturity value and total interest earned.

Formula

Simple interest:
A = P x (1 + r x t)

Compound interest:
A = P x (1 + r/n)^(n x t)

Where P = principal, r = annual rate, t = years, n = compounding periods per year.

Example

Example: Rs 2,00,000 at 9% for 10 years. Simple interest maturity = Rs 3,80,000. Compound (quarterly) maturity is higher because every quarter's interest starts earning more interest. Even at the same annual rate, compounding frequency can materially improve final corpus over long horizons.

Another example

Suppose two investors keep Rs 5,00,000 for 15 years at 10%. If one chooses simple interest and the other compound interest, the compound option creates a significantly larger end value. This is why long-term retirement and education goals usually prefer compounding products.

Scenario snapshots

FD versus growth product check

Compare annual compounding against simple-return assumptions before booking a long tenure.

Goal corpus back-calculation

Estimate whether current principal can reach target amount in the required time.

Rate sensitivity

Model 1-2% lower return to avoid overestimating final maturity.

Decision guide

Choose this when

  • ✓You want to compare simple and compound returns on the same principal.
  • ✓You are selecting tenure and compounding option for a fixed-income product.
  • ✓You are projecting long-term corpus for a defined goal.

Pick another route when

  • •You need product-specific tax, penalty, or exit-load modeling.
  • •Your cash flows are monthly contributions (use SIP or RD style calculators).
  • •You need inflation-adjusted real-return planning only.

Common mistakes to avoid

  • !Treating simple and compound returns as equivalent at long tenure.
  • !Assuming nominal annual rate guarantees real purchasing power growth.
  • !Ignoring that higher expected return usually comes with higher volatility.

Assumptions and disclaimers

Updated context: 2026

  • •Interest rate is assumed constant over full tenure.
  • •No tax deduction, TDS, or penalty logic is applied in this estimate.
  • •Compounding periods are standardized for comparison.

In practice (India)

Users often search for SI vs CI calculator, monthly compounding calculator, and compound interest formula with examples before selecting a savings product. This page is designed to answer those intent-rich queries directly with both math and practical interpretation.

For decision-making, run three scenarios: conservative return, base return, and optimistic return. Then compare results with FD, RD, SIP, and lumpsum outcomes to avoid anchoring your plan to a single assumption.

Benefits

  • ✓Instant SI vs CI comparison for better investment decisions.
  • ✓Shows maturity and interest split for clear interpretation.
  • ✓Supports multiple compounding frequencies for realistic planning.
  • ✓Helps build conservative, base, and optimistic corpus ranges.

Related calculators and guides

Frequently Asked Questions

Why is compound interest usually better than simple interest?
Because compound interest earns return on previously earned interest. Over longer tenures, this reinvestment effect increases maturity significantly.
Does monthly compounding always beat yearly compounding?
At the same annual rate and tenure, more frequent compounding usually gives a slightly higher maturity amount.
Can I use this for FD and debt fund comparisons?
Yes for directional planning. Product-specific taxes, penalties, and payout rules must be checked separately.
What rate should I enter?
Use realistic expected return, not best-case marketing return. Always test a lower-rate scenario as well.
Does this include inflation?
No. This tool shows nominal growth. For real purchasing power, adjust expected return by inflation.

This is an estimation tool. Actual returns vary by product terms, taxes, market behavior, and reinvestment discipline.

How we calculate

Estimates use the formula shown above. Rules and rates are checked against official India sources where applicable (Income Tax Act, RBI/NSC circulars, GST law). Last reviewed for 2026.

  • Interest rate is assumed constant over full tenure.
  • No tax deduction, TDS, or penalty logic is applied in this estimate.
  • Compounding periods are standardized for comparison.

Full methodology & sources