Interest Calculator: Simple aur Compound Interest — Loan, Savings aur FD Ke Liye Complete Guide Featured Image

Interest — Paison Ka Kiray

Interest basically paison ka "kiray" hai. Jab aap bank mein paisa rakhte ho, bank aapको interest deta hai (aapne paise "kiraye pe" diye hain bank ko). Jab aap loan lete ho, aap bank ko interest dete ho (aapne paisa "kiraye pe" liya hai).

Yeh simple concept hai — lekin calculation mein thoda dhyan chahiye. Simple interest aur compound interest mein bada farak hota hai jo saalon mein lakhs tak ho sakta hai.

Simple Interest (SI) — Seedha Calculation

SI = (Principal × Rate × Time) / 100

Jahan:
P = Principal amount
R = Annual interest rate (%)
T = Time in years

Total Amount = Principal + SI

Example: ₹50,000 loan, 10% rate, 3 saal:

  • SI = (50,000 × 10 × 3) / 100 = ₹15,000
  • Total repayment = ₹50,000 + ₹15,000 = ₹65,000

Simple interest typically short-term personal loans aur kuch government schemes mein use hoti hai.

Compound Interest (CI) — Thodi Zyada Math, Zyada Impact

CI = P × [(1 + R/100)^T - 1]
Total Amount = P × (1 + R/100)^T

Same example: ₹50,000, 10%, 3 saal, annually compounded:

  • Amount = 50,000 × (1.10)^3 = 50,000 × 1.331 = ₹66,550
  • CI = ₹66,550 - ₹50,000 = ₹16,550

Simple interest se ₹1,550 zyada — sirf 3 saal mein. 10-20 saal mein yeh gap bahut bada ho jaata hai.

Real Life Applications

Bank FD (Fixed Deposit)

Quarterly compound interest hoti hai. ₹2 lakh FD, 7% rate, 2 saal:

  • Quarterly rate = 7/4 = 1.75%
  • n = 8 quarters
  • Amount = 2,00,000 × (1.0175)^8 = ₹2,29,873

Home Loan EMI

Monthly reducing balance par interest calculate hoti hai — har EMI mein pehle interest kata, baad mein principal. Start mein zyada interest, end mein zyada principal — isliye prepayment early karna zyada faydemand hota hai.

Credit Card

Monthly compound, 3% per month = 36% annually. ₹20,000 outstanding, 6 mahine minimum payment:

  • Approximate balance = 20,000 × (1.03)^6 = ₹23,855
  • Extra ₹3,855 sirf interest mein gaya — bina kuch naya khareede!

Calculator Use Kaise Karen

  1. SI ya CI choose karo
  2. Principal, rate, aur time daalen
  3. Compounding frequency choose karo (CI ke liye)
  4. Result: Interest amount, total amount, aur year-by-year breakdown

FAQs

Q: Bank hamesha compound interest kyun use karta hai?
A: Deposits par bhi compound deta hai (aapke favor mein) aur loans par bhi compound leta hai (bank ke favor mein). Regulators ensure karte hain yeh fair basis par ho.

Q: Effective Annual Rate (EAR) kya hota hai?
A: Jab compounding monthly/quarterly ho, actual annual rate nominal rate se thoda zyada hota hai — ise EAR kehte hain. Banks sometimes EAR ke bajay nominal rate quote karte hain — dhyan rakhna.

Q: Kya main negative interest return calculate kar sakta hoon (loan loss)?
A: Haan — agar rate negative daalen toh calculator depreciation ya penalty calculation mein use ho sakta hai.

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