Money Basics: Budgeting, Saving and How Interest Works

By the Chundu Laboratories team · 5 min read · Updated 24 October 2026

Nobody is born knowing how to manage money, and schools rarely teach it. Yet a few basic ideas, a simple budget, an emergency fund and an understanding of interest, make a huge difference over a lifetime. This guide explains them in plain language. It is general information, not personal financial advice.

Step 1: Know where your money goes

A budget is simply a plan for your money. Start by tracking every expense for one month, using a notebook, a spreadsheet or the history in your UPI app. Group spending into categories such as rent, food, transport, phone and internet, loan payments, family support, shopping and entertainment. Most people are surprised by at least one category, often food delivery or small online purchases.

Step 2: Use a simple rule as a starting point

One popular guideline is 50/30/20:

About 50% of take-home income for needs: rent, groceries, bills, transport, minimum loan payments.
About 30% for wants: eating out, entertainment, shopping, trips.
About 20% for saving and paying off debt faster.

These numbers are not fixed laws. In expensive cities or on a low income, needs may take far more than half. The point is to decide in advance how much goes to saving, instead of saving whatever happens to be left over, which is usually nothing.

Step 3: Pay yourself first

Set up an automatic transfer to a separate savings account or recurring deposit on the day your salary arrives. Even a small amount, ₹500 or ₹1,000 a month, builds the habit. Money you never see in your spending account is much easier not to spend.

Step 4: Build an emergency fund

An emergency fund covers surprises: a job loss, a medical bill, a broken phone you need for work. A common target is three to six months of essential expenses, kept somewhere safe and easy to access, such as a savings account or a fixed deposit you can break if needed. Build it slowly. Even one month of expenses gives real peace of mind and keeps you away from expensive loans when something goes wrong.

How interest works

Interest is the price of money over time. When you save, the bank pays you interest. When you borrow, you pay it.

Simple interest is calculated only on the original amount. ₹1,00,000 at 8% simple interest earns ₹8,000 a year, so ₹80,000 over ten years, for a total of ₹1,80,000.

Compound interest is calculated on the original amount plus the interest already earned. The same ₹1,00,000 at 8% compounded yearly grows to about ₹2,15,900 after ten years. The extra ₹35,900 is interest earned on interest. The longer the time, the bigger the gap, which is why starting early matters more than starting big.

A handy shortcut is the Rule of 72: divide 72 by the yearly interest rate to estimate how many years it takes for money to double. At 8%, that is about 9 years. At 6%, about 12 years. It is an approximation, but a good one for everyday rates.

Compounding works against you on debt

The same maths makes debt expensive. Credit card interest on unpaid balances is often around 3% a month or more, which adds up to well over 30% a year. Paying only the "minimum due" keeps you in debt for a long time. If you use a credit card, try to pay the full statement amount every month. If you have several debts, pay at least the minimum on all of them and put any extra money toward the one with the highest interest rate.

Inflation: why saving alone is not enough

Prices rise over time. If inflation is 6% a year, prices roughly double in about 12 years (72 ÷ 6). Money sitting in a savings account earning less than inflation slowly loses buying power. That is why many people, once they have an emergency fund, consider long-term options suited to their goals. Before investing, learn the basics from trusted sources such as the investor-education material published by SEBI and RBI, and be very wary of anyone promising guaranteed high returns.

Protect what you build

Keep a record of your accounts, policies and nominees, and tell a trusted family member where it is.
Add nominees to bank accounts and deposits.
Consider health insurance early; one hospital stay can wipe out years of savings.
Never share OTPs or PINs; the fastest way to lose savings is fraud.

Start small, start now

You do not need a large income to begin. Track one month of spending, set one automatic saving transfer and pay one bill on time every month. Small, steady habits beat occasional big efforts. If you want help building a budget table, you can ask Jivra to make one from your categories, without sharing any account details.

Spotted a mistake? Email hello@chundulabs.in. Have a question? Ask Jivra.