Reverse CAGR Calculator
Pick what you want to find. Enter a growth rate (CAGR) and get what your money grows to, how much you need to invest today to hit a target, or how many years it will take. Every result also shows what it's worth in today's rupees. Investing monthly? Use the SIP calculator.
By Hardik Vegad, founder of WealthGamma · Last updated
Your money will grow to
₹3.11L
₹1,00,000 growing at 12% a year for 10 years. In today's money, that's worth ₹1.73L.
You invest
₹1,00,000
Wealth gained
₹2,10,585
Worth in today's money
₹1,73,429
Doubles every
6.1 years
How the money grows, year by year
- Value
- Value in today's money
- Amount invested
Year-by-year tableShowHide
| Year | Value | Gain | In today's money |
|---|---|---|---|
| 1 | ₹1,12,000 | ₹12,000 | ₹1,05,660 |
| 2 | ₹1,25,440 | ₹25,440 | ₹1,11,641 |
| 3 | ₹1,40,493 | ₹40,493 | ₹1,17,960 |
| 4 | ₹1,57,352 | ₹57,352 | ₹1,24,637 |
| 5 | ₹1,76,234 | ₹76,234 | ₹1,31,692 |
| 6 | ₹1,97,382 | ₹97,382 | ₹1,39,147 |
| 7 | ₹2,21,068 | ₹1,21,068 | ₹1,47,023 |
| 8 | ₹2,47,596 | ₹1,47,596 | ₹1,55,345 |
| 9 | ₹2,77,308 | ₹1,77,308 | ₹1,64,138 |
| 10 | ₹3,10,585 | ₹2,10,585 | ₹1,73,429 |
What is reverse CAGR?
Reverse CAGR starts from a growth rate you already know, or expect, and works out one of the other three numbers: what your money will grow to, how much you need to invest today to reach a target, or how many years it will take.
A normal CAGR (compound annual growth rate) calculation goes the other way: you know where an investment started and ended, and you find the yearly rate that connects them (the CAGR calculator does that). Reverse CAGR assumes the rate and solves for the rest, which is what you need when planning.
What is the reverse CAGR formula?
It's one formula, rearranged three ways depending on what you want to find:
Future value = Investment × (1 + CAGR)years
Investment = Future value ÷ (1 + CAGR)years
Years = ln(Future value ÷ Investment) ÷ ln(1 + CAGR)
Write the CAGR as a decimal (12% = 0.12). ln is the natural logarithm; in Excel, it's the LN function. To see what a result buys in today's money, divide it by (1 + inflation)years.
How much will ₹1 lakh grow at 12% CAGR in 10 years?
₹1 lakh growing at 12% a year becomes ₹3,10,585 in 10 years, a little over 3 times what you put in. After 6% inflation, that buys what ₹1,73,429 buys today.
- 1.1210 = 3.1058
- ₹1,00,000 × 3.1058 = ₹3,10,585
- Prices rise 6% a year, so ₹1 today costs ₹1.79 in 10 years
- ₹3,10,585 ÷ 1.79 = ₹1,73,429 in today's money
How much should you invest today to have ₹1 crore?
About ₹32,19,732, invested once, grows to ₹1 crore in 10 years at a 12% CAGR. Give it longer, or a higher rate, and you need far less today:
| Time to ₹1 crore | At 8% | At 10% | At 12% | At 15% |
|---|---|---|---|---|
| 10 years | ₹46.32L | ₹38.55L | ₹32.2L | ₹24.72L |
| 15 years | ₹31.52L | ₹23.94L | ₹18.27L | ₹12.29L |
| 20 years | ₹21.45L | ₹14.86L | ₹10.37L | ₹6.11L |
That ₹1 crore is in future rupees. At 6% inflation, ₹1 crore in 10 years buys what ₹55.84L buys today. For a goal priced in today's money, the goal SIP calculator does the inflation step for you.
How many years does it take to reach a target?
At 12% a year, ₹1 lakh takes 14 years 2 months to become ₹5 lakh. How long money takes to multiply depends only on the rate, not the amount:
| Money becomes | Years at 12% |
|---|---|
| 2 times | 6.1 |
| 3 times | 9.7 |
| 5 times | 14.2 |
| 10 times | 20.3 |
For doubling, the rule of 72 gets you close without a calculator: 72 ÷ 12 = 6 years, against the exact 6.1.
How do you use reverse CAGR for a stock?
Use it to check whether a price target is realistic. A ₹500 share growing at 15% a year would be worth about ₹1,006 in 5 years. If someone says it will hit ₹1,500 in 5 years, that needs a 24.6% CAGR, every year, for five years.
A share price usually can't outgrow the company's earnings for long. If the growth a target needs is far above what the business has managed, the target leans on hope, not numbers.
What CAGR should you assume?
Use a rate you'd be comfortable being wrong about. About 7% suits FD-like returns. For equity funds held for 10 years or more, 10% to 12% is a common planning range; plan on the low end and treat anything above it as a bonus.
Check the rate against inflation too. The RBI targets 4% consumer inflation within a band of 2% to 6%, so a 7% CAGR at 6% inflation grows your buying power only about 1% a year, before tax.
What does a reverse CAGR calculator not account for?
It assumes the same growth every single year. Four things it leaves out:
- Uneven returns. Real investments rise and fall; CAGR smooths a bumpy path into one number.
- Money added along the way. CAGR is for one amount invested once. For monthly investing, use the SIP calculator; to measure the return on money that went in at different times, use XIRR.
- Tax. Equity gains held over a year are taxed at 12.5% above ₹1.25 lakh a year; FD interest at your slab rate.
- Costs. Fund returns are after the expense ratio, but brokerage and exit loads are not.
For money invested once at a known rate, the lumpsum calculator gives the same future value with a year-by-year view.
Frequently asked questions
What is reverse CAGR?
Reverse CAGR starts from a growth rate you already know and works out one of the other numbers: what money grows to, how much to invest today for a target, or how many years it takes.
What is the reverse CAGR formula?
Future value = investment × (1 + CAGR)^years. Rearranged: investment = future value ÷ (1 + CAGR)^years, and years = ln(future value ÷ investment) ÷ ln(1 + CAGR).
How much should I invest today to get ₹1 crore in 10 years?
About ₹32,19,732 at a 12% CAGR. At 10% you'd need ₹38,55,433, and at 15% ₹24,71,847.
How long does it take to double money at 12% CAGR?
About 6.1 years. The rule of 72 gives a quick estimate: 72 ÷ 12 = 6 years.
What is the difference between CAGR and reverse CAGR?
CAGR finds the growth rate from a start value, an end value and the years. Reverse CAGR assumes the growth rate and finds the end value, the start value or the years.
Does reverse CAGR work for SIPs?
No. CAGR is for a single amount invested once. For monthly investments, use a SIP calculator, which counts each instalment separately.