Growth Planner
Compound Interest Calculator
See exactly how compound interest turns a lump sum (and an optional monthly top-up) into wealth — across yearly, half-yearly, quarterly, monthly, or daily compounding.
Configure Your Investment
Like an FD + top-up, or an RD sitting on top of a lump sum.
Results
Rule of 72: Years to Double Your Money
A quick mental-math shortcut — divide 72 by your annual rate to estimate doubling time.
Doubling Timeline
How ₹1L would double, and double again, at 9% p.a. with yearly compounding — no additions
Growth Over Time
Corpus value vs total contributed, year by year
Simple Interest vs Compound Interest
Same contributions, same rate — the only difference is whether interest earns interest
At maturity: compounding gets you ₹2.37 L, while simple interest on the same cash flows would only reach ₹1.90 L — a difference of ₹46,736 from compounding alone.
Year-by-Year Breakdown
Full compounding journey, period by period
| Period | Opening | Added | Interest | Closing |
|---|---|---|---|---|
| Year 1 | ₹1.00 L | --- | ₹9,000 | ₹1.09 L |
| Year 2 | ₹1.09 L | --- | ₹9,810 | ₹1.19 L |
| Year 3 | ₹1.19 L | --- | ₹10,693 | ₹1.30 L |
| Year 4 | ₹1.30 L | --- | ₹11,655 | ₹1.41 L |
| Year 5 | ₹1.41 L | --- | ₹12,704 | ₹1.54 L |
| Year 6 | ₹1.54 L | --- | ₹13,848 | ₹1.68 L |
| Year 7 | ₹1.68 L | --- | ₹15,094 | ₹1.83 L |
| Year 8 | ₹1.83 L | --- | ₹16,452 | ₹1.99 L |
| Year 9 | ₹1.99 L | --- | ₹17,933 | ₹2.17 L |
| Year 10 | ₹2.17 L | --- | ₹19,547 | ₹2.37 L |
| Total | --- | ₹0 | ₹1.37 L | ₹2.37 L |
Compound Interest: The Engine Behind SIP Wealth
Compound interest means the interest you earn is added back to your principal, so the next round of interest is calculated on a bigger base — interest earning interest. This compound interest calculator shows exactly how that snowball effect plays out, whichever compounding frequency you choose.
FD quarterly compounding vs mutual fund Growth option: Bank Fixed Deposits typically compound interest quarterly, which is why the effective yield on an FD is always a touch higher than its quoted “annual” rate. A mutual fund’s Growth option reinvests all gains back into the NAV automatically — effectively compounding every business day the market is open — which is one reason a long-tenure SIP or lumpsum in equity/hybrid funds can compound faster than a similarly-rated FD over the long run, though it carries market risk that an FD does not.
The longer the money stays invested, the larger the gap between simple and compound growth becomes — which is exactly why starting early matters more than the exact rate you earn.
Want your money compounding at a better effective rate?
Your Trustner Relationship Manager can map this compounding math onto a Growth-option mutual fund plan suited to your goal and time horizon.
Calculator results are for illustration purposes only. Actual returns may vary based on market conditions, fund performance, and other factors. Mutual fund investments are subject to market risks. Read all scheme-related documents carefully before investing. Past performance does not guarantee future returns.
Compound interest — why time is the real multiplier
Compound interest is interest earned on your interest, not just your original amount. Its defining feature is that the growth curve starts slow and then steepens sharply — most of the wealth in a long compounding plan is created in its final years. That is why starting early, even with a smaller amount, so often beats starting later with a larger one.
This calculator shows how a principal grows under compounding for a given rate, compounding frequency and number of years, and separates your contribution from the interest earned. Two things move the outcome more than people expect: the number of years (time has an outsized effect) and the rate, because small differences compound into large gaps over decades.
How this calculator works
- 1Enter the principal, the annual interest rate, the compounding frequency and the number of years.
- 2The calculator applies the compound-interest formula and shows the maturity value.
- 3It splits the result into your principal and the interest earned on it.
Frequently asked questions
What is the difference between simple and compound interest?
Simple interest is calculated only on the original principal, so it grows in a straight line. Compound interest is calculated on the principal plus all previously earned interest, so it grows faster and faster over time. Over long periods the gap between the two becomes very large.
Does compounding frequency matter?
Yes, a little. More frequent compounding (monthly vs annually) produces a slightly higher result for the same nominal rate, because interest is added to the balance more often. The effect is modest compared with the impact of the rate and the number of years, but it is real.
What is the Rule of 72?
The Rule of 72 is a quick mental shortcut: divide 72 by the annual return to estimate how many years it takes money to double. At 8% a year, money roughly doubles in 9 years; at 12%, in about 6. It is an approximation, but a handy way to feel the power of compounding.
Illustrative only; actual returns vary and are not guaranteed.
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