trending_up

Compound Interest Calculator

Calculate CI on any investment or loan — any compounding frequency. Get maturity amount, EAR, Rule of 72, SI comparison, year-wise growth table, and inflation-adjusted real returns instantly.

functions CI Formula compare_arrows All Frequencies speed EAR + Rule of 72
trending_up Compound Interest Calculator
₹
% pa
% pa

₹1 Lakh at 8% for 20 Years — SI vs CI: The ₹2 Lakh Difference

Einstein ne kaha tha — "Compound interest is the eighth wonder of the world. He who understands it, earns it. He who doesn't, pays it."

Ye quote probably Einstein ne nahi kaha — lekin concept bilkul sach hai.

Ek example dekho. Arjun ne ₹1,00,000 invest kiye 20 saal ke liye.

Simple Interest pe (8%):
Har saal ₹8,000 interest. 20 saal mein: ₹1,60,000 total interest.
Final amount: ₹2,60,000

Compound Interest pe (8%, annual):
Pehle saal: ₹8,000. Doosre saal: ₹8,640 (₹1,08,000 pe). Teesre saal: ₹9,331...
20 saal mein: ₹3,66,094 total interest. Final amount: ₹4,66,094

Difference: ₹2,06,094 — sirf compounding ki wajah se.

Same principal. Same rate. Same time. Lekin compounding ne almost double kar diya. Aur agar quarterly compound kiya hota? ₹4,87,544 — aur ₹21,450 zyada!

India mein almost sab major investment instruments compound interest use karte hain — FD, RD, PPF, EPF, mutual funds, NPS. Aur sab major loans bhi — home loan, personal loan, credit card. Dono sides pe compounding kaam karta hai — tumhare favor mein jab invest karte ho, tumhare against jab borrow karte ho.

faydemand.in ka Compound Interest Calculator ye complete picture deta hai:

  • Standard CI formula — annual, semi-annual, quarterly, monthly, daily, continuous
  • SI vs CI comparison — exact rupee difference
  • Effective Annual Rate (EAR) — true return considering compounding
  • Rule of 72 — instant doubling time
  • Inflation-adjusted real returns
  • All 6 compounding frequencies simultaneously — side by side
  • Year-wise growth table

What Is Compound Interest?

Compound Interest (CI) ek interest calculation method hai jisme interest sirf original principal pe nahi — balki accumulated interest pe bhi calculate hoti hai. Interest on interest — ye compounding ka core concept hai.

Compounding Frequency — Impact on Returns

Frequency n Value Used In
Annual1PPF, NSC, some FDs
Semi-annual2Some bonds
Quarterly4Most Indian FDs, RDs
Monthly12Savings accounts, home loans
Daily365Some international instruments
Continuous∞Theoretical maximum

CI Power at Different Rates (₹1,00,000 for 20 Years)

Rate SI Total CI Total (Annual) CI Advantage
6%₹2,20,000₹3,20,714+₹1,00,714
8%₹2,60,000₹4,66,096+₹2,06,096
10%₹3,00,000₹6,72,750+₹3,72,750
12%₹3,40,000₹9,64,629+₹6,24,629

CI Formula & Notation

Primary Compound Interest Formula

A = P × (1 + R/n)^(n×T)
CI = A − P = P × [(1 + R/n)^(n×T) − 1]

Annual (n=1): A = P × (1 + R)^T
Continuous: A = P × e^(R×T)

Find P: P = A ÷ (1 + R/n)^(n×T)
Find R: R = n × [(A/P)^(1/(n×T)) − 1]
Find T: T = ln(A/P) ÷ [n × ln(1 + R/n)]
EAR: (1 + R/n)^n − 1

Variable Definitions

Variable Meaning Example
PPrincipal (initial amount)₹1,00,000
RAnnual interest rate (decimal)0.10 for 10%
nCompounding periods per year4 for quarterly
TTime in years5
ATotal amount at maturity₹1,63,862
CICompound Interest earned₹63,862
EAREffective Annual Rate10.38% for 10% quarterly

Compounding Frequency Impact (₹1,00,000 at 10% for 5 Years)

Frequency n Maturity Amount EAR
Annual1₹1,61,05110.00%
Semi-annual2₹1,62,88910.25%
Quarterly4₹1,63,86210.38%
Monthly12₹1,64,53310.47%
Daily365₹1,64,86110.52%
Continuous∞₹1,64,87210.52%

5 Worked Examples

Example 1 — FD: Quarterly Compounding

Arjun: FD ₹5,00,000 at 7.5%, quarterly, 3 years
A = ₹5,00,000 × (1 + 0.075/4)^(4×3) = ₹5,00,000 × (1.01875)^12 = ₹6,25,292
CI = ₹1,25,292 | EAR = 7.71% | SI for same = ₹6,12,500 | CI advantage: ₹12,792

Example 2 — Reverse: Goal-Based Planning

Priya wants ₹10,00,000 in 5 years, 8% quarterly compounding
P = ₹10,00,000 ÷ (1.02)^20 = ₹10,00,000 ÷ 1.48595 = ₹6,72,971
Invest ₹6.73L today → ₹10L in 5 years ✅

Example 3 — Credit Card: Monthly CI Trap

Vikash: ₹50,000 credit card at 3.5%/month
EAR = (1.035)^12 − 1 = 51.1%
After 1 year (no payment): ₹50,000 → ₹75,557. FD earns ₹3,956/year. Net damage: ₹29,513/year

Example 4 — PPF vs FD: Annual vs Quarterly

PPF: 7.1% annual compounding. FD: 7% quarterly (EAR 7.186%). ₹1.5L/year, 15 years.
PPF: ~₹40,68,209 | FD: ~₹40,90,000 | FD slightly better on EAR.
BUT: PPF is EEE tax-free — for 30% bracket, PPF significantly better post-tax.

Example 5 — Early Start: 10 Years Make ₹1.79 Crore Difference

Kavya (25) vs Rohan (35), same ₹5,00,000 at 12% annual CI, retire at 60.
Kavya (35 years): ₹5,00,000 × (1.12)^35 = ₹2,64,00,000 (₹2.64 crore)
Rohan (25 years): ₹5,00,000 × (1.12)^25 = ₹85,00,000
₹1.79 crore more — just by starting 10 years earlier. Time is the most powerful variable in CI.

How to Use the CI Calculator — Step by Step

1
Enter Principal Amount
Type the initial investment or loan amount (₹). This is the base on which compound interest is calculated.
2
Enter Annual Interest Rate
Enter the nominal annual rate as stated by the bank — e.g., 7.5 for 7.5% pa. Do not enter monthly rate here.
3
Select Compounding Frequency
Choose from the dropdown: Annual (PPF, NSC), Semi-annual (some bonds), Quarterly (most Indian FDs), Monthly (savings accounts, loans), Daily, or Continuous.
4
Enter Time Period
Type the duration. Select Years or Months from the unit dropdown. Example: 30 months = select Months, enter 30.
5
Enter Inflation Rate (Optional)
Default is 5.5%. This unlocks inflation-adjusted real return — shows actual purchasing power growth, not just nominal.
6
Read Results
Maturity Amount, CI earned, EAR, Rule of 72 (doubling time), SI comparison, and CI advantage — all calculated instantly.
7
Check Frequency Comparison Table
See all 6 compounding frequencies simultaneously for the same P, R, T — understand the impact of higher frequency compounding.
8
Review Year-wise Table
Track how CI and SI diverge year over year — exponential vs linear growth visible clearly.
9
Check Real Returns
Inflation box shows real CAGR and real value in today's rupees — honest wealth creation picture beyond nominal numbers.
10
Share via WhatsApp or PDF
Share CI results with family — useful for family financial planning discussions, FD comparisons, and loan analysis.

6 Pro Tips for Compound Interest

Check compounding frequency in FDs — same rate, quarterly beats annual

Bank A: 7.5% annual. Bank B: 7.5% quarterly. EAR: 7.5% vs 7.71%. ₹5L, 5 saal: Bank A ₹7,17,359 vs Bank B ₹7,27,094. ₹9,735 extra sirf frequency se. FD comparison mein hamesha EAR compare karo — nominal nahi.

Use Rule of 72 as a mental math shortcut

Years to double = 72 ÷ Rate. EPF 8.25% → 8.7 saal. PPF 7.1% → 10.1 saal. Equity 12% → 6 saal. Inflation 6% → prices 12 saal mein double. Quick sanity check for any investment without a calculator.

Reinvestment is what makes CI real — choose cumulative FD

Quarterly interest payout FD = effectively SI (principal stays same). Cumulative FD reinvests interest — full CI power. Same 7.5% rate: Payout FD ₹37,500 interest in year 1 vs Cumulative FD ₹38,457. Har saal difference grow karta hai. Always choose cumulative for wealth building.

Credit card CI — 51% EAR is your worst financial enemy

3.5% monthly = 42% nominal = 51.1% EAR. ₹30,000 outstanding, minimum payments, 1 year: balance grows to ₹45,000+. Priority #1: Clear credit card every month. Agar revolving credit hai — personal loan at 12-14% leke balance transfer karo. CI rate dramatic drop hoga.

Start early — 10 extra years = crore-level difference

25 pe ₹1,000/month SIP, 12%, 35 years: ₹3.53 crore. 35 pe same shuru karo, 25 years: ₹1.89 crore. 10 saal ki delay = ₹1.64 crore less. faydemand.in CI Calculator + SIP Calculator pe compare karo — numbers se motivation aati hai.

Real returns matter — don't get fooled by nominal rate

FD 7.5%, inflation 6%: Real return sirf 1.5%. ₹5L FD 10 years: Nominal ₹10.3L but real value ₹7.55L (today's purchasing power). Equity 13% nominal, 6% inflation: Real 6.6%, real value ₹14.6L. Real returns compare karo to judge true wealth creation.

5 Key Benefits of Understanding Compound Interest

  • Multi-Mode Calculator — One Tool for All CI Calculations — Standard CI, EAR, Rule of 72, SI comparison, inflation adjustment, frequency comparison — sab ek tool mein. No need to search alag alag calculators. Complete CI financial mathematics suite.
  • Compounding Frequency Comparison — Hidden Value Visible — Annual vs quarterly vs monthly simultaneously — one click mein sab results side by side. ₹10L, 10 years, 8%: Annual ₹21.59L vs Monthly ₹22.20L. ₹61,000 difference clearly shown — FD selection mein game-changing insight.
  • Effective Annual Rate (EAR) — True Apples-to-Apples Comparison — Different banks different compounding frequencies use karte hain. EAR levels the playing field — 7.5% quarterly vs 7.6% annual: EAR 7.71% vs 7.60%. Calculator automatically reveals which is actually better.
  • CI vs SI Visualization — Compounding Power Made Tangible — Abstract "compound interest powerful hai" vs concrete "₹1L, 15 years, 10%: SI ₹2.5L, CI ₹4.18L — ₹1.68L difference." Bar chart visualization makes exponential vs linear growth immediately visible. Financial literacy through data.
  • Real Return Clarity — Honest Wealth Assessment — Nominal returns investors ko mislead karte hain. faydemand.in explicitly shows both nominal and real (inflation-adjusted). True wealth creation requires beating inflation — calculator makes this visible and actionable. Compare FD real returns vs equity real returns honestly.

5 Common Compound Interest Mistakes

Comparing FDs on nominal rate — use EAR

Bank A: 7.5%, Bank B: 7.4% — Bank A better lagta hai. But Bank A quarterly (EAR 7.71%) vs Bank B monthly (EAR 7.65%) — actually Bank A wins. Lekin agar Bank B monthly EAR 7.72% hota toh Bank B better. Nominal rate se FD compare karna = wrong decision. Always EAR basis pe compare karo.

Payout FD lena for wealth building — always take cumulative

Quarterly interest payout mein CI break ho jaata hai — effectively simple interest. Principal same rehta hai. Cumulative FD (reinvestment) = full CI benefit. Wealth building ke liye: Hamesha cumulative FD. Regular income chahiye toh payout theek hai — but wealth growth mein significantly kam milega.

Monthly rate ko annual treat karna — always annualize

Credit card "1.5% per month" = 18% annual nominal = 19.56% EAR. Moneylender "2% per month" = 24% annual = 26.82% EAR. Monthly rates quoted by lenders — always convert to annual before comparing. faydemand.in CI Calculator mein frequency dropdown use karo — enter monthly rate if needed, it converts automatically.

Using CI formula for EMI loans — wrong tool

Home loan, personal loan mein principal reduces with each EMI payment — standard CI formula nahi chalta (that assumes fixed principal). EMI loan pe CI formula use karo toh drastically wrong (higher) answer aata hai. EMI loans ke liye faydemand.in Home Loan or Personal Loan EMI Calculator use karo — wo reducing balance method use karta hai.

Over-optimizing on continuous compounding — focus on rate and time

Monthly vs continuous compounding: ₹1L, 10%, 5 years: ₹1,64,533 vs ₹1,64,872. Difference ₹339 — negligible. Real focus karo: Better rate (0.25% more matters far more), Longer time horizon, Right instrument. Continuous compounding is theoretical — don't obsess over it when daily and monthly are practically indistinguishable.

5 Real-World Use Cases

FD Selection — Which Bank Is Actually Better? Meena: Bank A 7.5% quarterly, Bank B 7.45% monthly, Bank C 7.6% annual. EAR: A=7.714%, B=7.707%, C=7.600%. 3 years ₹10L: A ₹12,50,584, B ₹12,50,120, C ₹12,46,000. Bank A wins despite not having highest nominal rate. faydemand.in EAR calculation ne ₹4,584 better decision enable kiya.
Education Corpus Planning — Reverse CI Rohan (32), daughter college 11 saal mein, target ₹25L, PPF 7.1% annual. P = ₹25L ÷ (1.071)^11 = ₹11,77,012. Aaj ₹11.77L invest karo PPF mein → 11 saal mein ₹25L. Alternative: ₹7,500/month SIP at 12% for 11 years. CI calculation gave exact planning number — specific action instead of vague "save more."
Credit Card vs Personal Loan Decision Kavya: ₹75,000 credit card outstanding at 3.5%/month (EAR 51.1%). Personal loan at 14%: Total ₹81,119. Credit card annual interest (no payment): ₹38,325. Saving: ₹32,206/year by switching to personal loan. Kavya took personal loan, cleared card. CI calculation → life-changing financial decision.
Early vs Late Investment Comparison Arjun (25) vs Priya (35), same ₹2L at 12% CI till 60. Arjun (35 years): ₹1.06 crore. Priya (25 years): ₹34 lakh. ₹71.6 lakh more just for starting 10 years earlier. This scenario shown to 25-year-olds = instant motivation to invest now. Most powerful financial literacy demonstration in CI Calculator.
NSC vs FD Comparison Sunita: NSC 7.7% annual vs FD 7.5% quarterly, ₹3L, 5 years. NSC: ₹4,34,280. FD: ₹4,35,165. FD wins by ₹885 on EAR basis. But NSC has Section 80C tax benefit, FD interest taxable. For 30% bracket: NSC net better by significant margin. CI gave starting numbers — tax analysis gave final decision. Complete picture.

Frequently Asked Questions

What is the compound interest formula in India?expand_more

Compound Interest formula hai: CI = P × [(1 + R/n)^(n×T) − 1]. Jahan P = Principal, R = Annual rate (decimal mein), n = Compounding frequency per year (1=annual, 2=semi-annual, 4=quarterly, 12=monthly), T = Time in years. Total Amount = P × (1 + R/n)^(n×T). Example: ₹1,00,000 at 10% for 3 years quarterly compounding: A = 1,00,000 × (1 + 0.10/4)^(4×3) = 1,00,000 × (1.025)^12 = ₹1,34,489.

What is the difference between simple interest and compound interest?expand_more

Simple Interest: Sirf original principal pe interest lagti hai — har saal same amount. Compound Interest: Principal + accumulated interest dono pe interest lagti hai — interest on interest. Same ₹1 lakh, 12%, 10 years: SI = ₹1,20,000 interest. CI (annual) = ₹2,10,585 interest — nearly double! Compounding frequency badho toh CI aur badh jaati hai. Investors ke liye CI better hai. Borrowers ke liye SI better hota hai.

How does compounding frequency affect returns?expand_more

Compounding frequency jitni zyada — returns utne zyada. ₹1,00,000 at 12% for 5 years: Annual compounding: ₹1,76,234. Semi-annual: ₹1,79,085. Quarterly: ₹1,80,611. Monthly: ₹1,81,670. Daily: ₹1,82,194. Difference annual vs monthly: ₹5,436 on ₹1L. On ₹10 lakh over 20 years — difference lakhs mein hota hai. FD rates dekhte time compounding frequency note karo — same rate pe quarterly FD better than annual.

What is the Rule of 72 in compound interest?expand_more

Rule of 72 ek mental math shortcut hai: Paisa double hone mein kitne saal lagenge = 72 ÷ Annual Interest Rate. Example: 8% rate pe — 72 ÷ 8 = 9 saal mein double. 12% pe — 72 ÷ 12 = 6 saal. 6% pe — 72 ÷ 6 = 12 saal. Ye approximation compound interest pe based hai — simple interest pe accurate nahi. faydemand.in CI Calculator mein Rule of 72 automatically dikhata hai for your entered rate.

Which investments in India use compound interest?expand_more

Compound interest use karne wale instruments India mein: Fixed Deposits (quarterly compounding typically). Recurring Deposits. Public Provident Fund (annual compounding). National Savings Certificate (annual compounding). Mutual Funds (continuous compounding via NAV growth). EPF (annual compounding). Savings Account interest (quarterly). Home loans, personal loans, credit cards (monthly compounding — borrower pe). ELSS, NPS — market-linked compounding.

What is continuous compounding and how is it calculated?expand_more

Continuous compounding = infinite compounding periods — theoretical maximum. Formula: A = P × e^(R×T), jahan e = Euler's number (2.71828). Example: ₹1,00,000 at 10% for 5 years continuous: A = 1,00,000 × e^(0.10×5) = 1,00,000 × e^0.5 = ₹1,64,872. vs Annual compounding: ₹1,61,051. Difference small hai — practical investing mein monthly compounding aur continuous compounding ka difference negligible hota hai.

How do I find the principal if I know maturity amount, rate, and time?expand_more

Reverse CI formula: P = A ÷ (1 + R/n)^(n×T). Example: 3 saal baad ₹1,50,000 chahiye, rate 10% quarterly compounding. P = 1,50,000 ÷ (1 + 0.10/4)^(4×3) = 1,50,000 ÷ (1.025)^12 = 1,50,000 ÷ 1.3449 = ₹1,11,531. Matlab aaj ₹1,11,531 invest karo toh 3 saal mein ₹1,50,000 milega.

What is effective annual rate (EAR)?expand_more

Effective Annual Rate (EAR) = actual annual return considering compounding frequency. Formula: EAR = (1 + R/n)^n − 1. Example: 12% nominal rate, monthly compounding: EAR = (1 + 0.12/12)^12 − 1 = (1.01)^12 − 1 = 12.68%. Matlab nominal 12% monthly compounding = effective 12.68% annual. FD comparison mein EAR use karo — different banks different compounding frequencies use karte hain — EAR se accurate comparison hota hai.

How does inflation affect compound interest returns?expand_more

Inflation CI returns ko erode karti hai. Real return = Nominal return − Inflation rate (approximate). ₹1L at 8% CI for 10 years: Nominal maturity ₹2,15,892. Inflation 5% per year: Real value = ₹2,15,892 ÷ (1.05)^10 = ₹1,32,477 in today's purchasing power. Real CAGR = [(1.08)÷(1.05)] − 1 = 2.86%. faydemand.in CI Calculator inflation-adjusted real returns bhi calculate karta hai — honest wealth creation picture.

Is compound interest on loans bad for borrowers?expand_more

Borrowers ke liye CI costly hai — especially credit cards (3-3.5% monthly = 42%+ annual effective rate). Home loan, personal loan: Monthly reducing balance CI — manageable lekin SI se zyada. Strategy: Prepay loans early — CI pe total interest savings dramatic hote hain early prepayment pe. ₹50L home loan 20 years 9% — agar 5 saal baad ₹5L prepay karo: ₹8+ lakh interest saved.

Related Calculators

CI concept samajhne ke baad in tools se apna complete financial plan build karo:

calculate Simple Interest CalculatorSI vs CI direct comparison — difference clearly samjho savings FD CalculatorFixed Deposit maturity with quarterly compounding trending_up SIP CalculatorMonthly investment pe CI ka power — mutual fund corpus account_balance PPF CalculatorPPF annual compounding — 15 year corpus projection