Finance Calculators · 15 guides

Money Maths Explained: Loans, Investments and Tax

The formulas behind the numbers banks and fund houses quote you, worked through step by step: EMI, SIP and lumpsum returns, PPF and EPF, FD and RD interest, GST, CAGR, inflation and retirement planning. Every example is calculated exactly, so you can check it yourself. These guides are for information only, not financial advice.

15 articles in Finance Calculators

CAGR Formula With Examples: How to Calculate Growth Rate
The CAGR formula with three worked examples, tested Excel formulas (RRI and the power method), the mistakes that skew the result, and when to use XIRR.
4 Oct 20268 min read
Compound Interest Formula With Examples (Yearly, Quarterly, Monthly)
The compound interest formula worked on ₹1 lakh with yearly, quarterly and monthly compounding, plus simple vs compound interest and the effective rate.
4 Oct 20269 min read
EMI Formula Explained: How to Calculate Your Loan EMI (With Examples)
The EMI calculation formula worked through step by step, how rate and tenure change your EMI and total interest, and what a prepayment really saves you.
4 Oct 20268 min read
GST Calculation Formula: Add or Remove GST With Examples
The GST calculation formula both ways: add GST to a price or remove it from a total, with worked examples, the CGST and SGST split and invoice rounding tips.
4 Oct 20267 min read
Home Loan Prepayment: Reduce EMI or Tenure? The Maths Explained
Home loan prepayment: reduce EMI or tenure? See worked numbers on a ₹40 lakh loan, the prepay-or-invest maths and the RBI rules on prepayment charges.
4 Oct 20268 min read
SIP vs Lumpsum: Which Is Better? Worked Examples in INR
SIP vs lumpsum with real maths: why a lump sum wins in steady markets, when SIP averaging helps, STP as a middle path, and a checklist to help you decide.
4 Oct 20268 min read
CTC vs In-Hand Salary: Why Your Take-Home Pay Is Lower
CTC vs in-hand salary with a ₹12 lakh breakup: what employer PF, gratuity, tax and variable pay take out of your CTC, and what to ask HR before you accept.
4 Oct 20268 min read
FD vs RD: Which Earns More? Interest Formulas and Examples
FD vs RD compared on the same ₹1.2 lakh: the interest formulas, why an RD earns about half the interest, which suits your savings, and the TDS and exit rules.
4 Oct 20267 min read
Home Loan Eligibility on Salary: How Much Can You Borrow?
Home loan eligibility on salary, worked out: the FOIR formula lenders use, examples for ₹30,000, ₹50,000 and ₹1 lakh a month, and the ways to borrow more.
4 Oct 20268 min read
How EPF Interest Is Calculated: Monthly Example With Numbers
How EPF interest is calculated on your monthly running balance and credited each March, with a 12-month worked example, the EPS split and how VPF adds to it.
4 Oct 20268 min read
SIP Calculation Formula: How Your SIP Returns Are Worked Out
The SIP calculation formula worked through on ₹5,000 a month, the Excel FV version, why calculators disagree, and how XIRR shows what your SIP really earned.
4 Oct 20269 min read
Flat vs Reducing Interest Rate: Why 8% Flat Isn't 8%
Flat vs reducing interest rate on one ₹5 lakh loan: 8% flat costs ₹1.2 lakh in interest, the same as 14.55% reducing. Convert any rate and compare offers.
4 Oct 20267 min read
Gratuity Calculation Formula With Examples (and What Changed)
The gratuity calculation formula, 15/26 of last wages for each year, worked through with examples, plus what the 2025 labour codes changed and the tax rules.
4 Oct 20268 min read
How PPF Interest Is Calculated (and Why the 5th of the Month Matters)
How PPF interest is calculated on the lowest balance after the 5th, with worked numbers for April vs monthly deposits and a 15-year maturity at 7.1%.
4 Oct 202610 min read
Rule of 72: How Long Will Your Money Take to Double?
The rule of 72 says money doubles in 72 ÷ rate years. See how accurate it is from 4% to 15%, how to use it for inflation and debt, and when 70 or 69.3 fits.
4 Oct 20266 min read

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