See exactly how your money grows.

Enter a principal, a rate, and a term. PaisaCalc works out the simple or compound interest and lays out every year of growth — no spreadsheet required.

8 free calculators in one place

Pick a tool below, or scroll down to use the Interest Calculator right here on this page.

From date
To date Use today
Dates are calculated in IST (India Standard Time).
Total amount after 5 years
₹1,40,000
Principal₹1,00,000
Interest earned₹40,000
Balance growth, year by year
Principal
Interest earned
Amount (₹)
Year
Each bar is your balance at the end of that year. The green base is your principal — it never changes. The gold on top is interest earned so far. The dashed line marks your original principal, so anything above it is pure interest. Hover a bar for exact figures.

Same numbers, both ways

Using the principal, rate, and duration from the calculator above — here's what you'd end up with under each method.
Simple interest
₹1,40,000
Compound interest
₹1,46,933
At these numbers, compounding gets you ₹6,933 more over this period — a 4.9% difference. The gap widens the longer the money stays in.

Year-by-year ledger

How the balance builds up, year after year.
Swipe left/right to see all columns →
YearOpening balanceInterestClosing balance

Simple vs. compound interest — what's the difference?

Both are ways of calculating what you earn (or owe) on money over time, but they grow very differently — and which one applies to you usually depends on which side of the deal you're on.

You're earning interest

Savings, deposits & investments

Money sitting in an FD, RD, savings account, or mutual fund almost always compounds — your gains get reinvested automatically, so compound interest is doing the work for you.

  • Fixed & recurring deposits
  • Savings accounts
  • SIPs & mutual funds
You're paying interest

Loans & borrowed money

Most personal, auto, and consumer loans in India use simple interest on a reducing balance — you only pay interest on what's still outstanding, not the original amount.

  • Personal & auto loans
  • Informal / friends & family loans
  • Some short-term business loans

Simple interest

Simple interest is calculated only on the original principal, every single period. The interest amount stays exactly the same year after year, so your money grows in a straight line.

Interest = Principal × Rate × Time / 100

Example: ₹1,00,000 at 8% for 5 years earns ₹8,000 every year, for a flat ₹40,000 total — regardless of which year you're in.

Compound interest

Compound interest is calculated on the principal plus any interest already earned. Each period's interest gets added back in, so the amount it's calculated on keeps growing — and so does your money, faster each year.

Amount = Principal × (1 + Rate/n)n × Time

Example: the same ₹1,00,000 at 8% compounded annually earns ₹8,000 in year one, but ₹8,640 in year two, ₹9,331 in year three — growing each year instead of staying flat.

Where you'll actually run into these

🏦Fixed & recurring deposits
Compound
~6.5–7.5% p.a. · compounded quarterly

Indian banks compound FDs and RDs quarterly by default, even though the rate is quoted annually. See the FD Calculator.

💰PPF & post office schemes
Compound
~7–7.5% p.a. · compounded annually, govt-set

PPF, NSC, and KVP are government-backed, tax-saving, and compound annually at a rate reset every quarter by the government — low risk, long lock-in.

💳Credit cards
Compound
~36–42% p.a. effective · compounds daily

Unpaid credit card balances compound daily — why a small unpaid balance can balloon fast if left over a few months.

📈SIPs & mutual funds
Compound
~10–12% p.a. long-term avg · market-linked

Returns are reinvested every cycle, so the earlier you start, the more time compounding gets to work. See the SIP Calculator.

🚗Personal & auto loans
Simple
~9–14% p.a. · reducing balance

Usually simple interest on the reducing balance — each EMI pays interest only on what's still outstanding. See the EMI Calculator.

🤝Informal / personal loans
Simple
No fixed range · usually flat, negotiated

Money lent to friends, family, or through a private agreement is almost always tracked as flat, simple interest — easy to work out by hand.

🏦Savings accounts
Compound
~2.5–4% p.a. · compounded quarterly

Interest is usually calculated daily on your closing balance and credited quarterly — compounding, just at a much lower rate.

What if you pay off part of a loan early?

Paying a lump sum in the middle of a loan doesn't just chip away at the balance — it changes how much interest builds up for the rest of the term, because the remaining interest is recalculated on a smaller principal. Here's a worked example on a simple-interest, reducing-balance loan:

Years 1–2 (before prepayment)
Interest = P × R × t / 100
₹5,00,000 × 10% × 2 = ₹1,00,000 interest
Prepayment at end of year 2
New principal = P − prepayment
₹5,00,000 − ₹1,00,000 = ₹4,00,000
Years 3–5 (remaining term)
Interest = new P × R × remaining t / 100
₹4,00,000 × 10% × 3 = ₹1,20,000 interest
Total interest, 5 years
₹1,00,000 + ₹1,20,000
₹2,20,000 (vs ₹2,50,000 with no prepayment)
Prepaying ₹1,00,000 at year 2 saves ₹30,000 in total interest on this loan — because the last 3 years of interest are charged on ₹4,00,000 instead of the full ₹5,00,000. The same logic applies to compound-interest products like FDs: withdrawing part of it early means everything after that point compounds on the smaller, reduced balance.
Model your own loan with a prepayment →

Common questions

Is compound interest always better than simple interest?

If you're the one earning interest (savings, deposits, investments), compound interest works in your favor and grows your money faster over time. If you're the one paying interest (a loan), compound interest means you pay more overall than you would with simple interest — so it depends on which side of the deal you're on.

What does "compounding frequency" mean?

It's how often interest gets added back into the principal — annually, semi-annually, quarterly, or monthly. The more frequently interest compounds, the faster your money grows, even at the same annual rate, because interest starts earning its own interest sooner.

How is interest calculated for a period that isn't a whole number of years?

This calculator works it out from your exact From and To dates, down to the day — including part-years, part-months, and leftover days — rather than rounding to the nearest whole year.

Which one do banks use for fixed deposits (FDs) and loans?

Most bank FDs and recurring deposits use compound interest, usually compounded quarterly. Most personal and vehicle loans use simple interest calculated on the reducing balance, though the exact method varies by lender — always check your loan or deposit agreement for the specific method used.

What happens if I pay off part of a loan before the tenure ends?

The interest for the remaining term gets recalculated on the smaller, reduced principal — not the original amount — so you pay less total interest the earlier you prepay. For example, prepaying ₹1,00,000 on a ₹5,00,000 / 10% / 5-year simple-interest loan at the 2-year mark saves ₹30,000 in interest overall.

Where do I actually run into simple vs. compound interest day to day?

Compound interest shows up wherever your money (or debt) is left to grow on itself — FDs, RDs, savings accounts, SIPs, and unpaid credit card balances. Simple interest shows up mostly on the borrowing side — personal loans, auto loans, and informal loans, calculated on the reducing balance as you repay.

All PaisaCalc calculators

Eight free tools, all built the same way — exact date-based math, year-by-year breakdowns, and no signup.