CAGR Calculator

Imagine your money as a tree that grows at a steady rate each year. CAGR tells you what that steady growth rate would need to be to get from your starting amount to your ending amount over the time period you specify. Unlike simple averages that can hide volatility, CAGR smooths out the ups and downs to show the true underlying growth rate.

The magic happens through compounding - each year's growth builds on the previous year's total, not just the original amount. A $10,000 investment growing at 10% CAGR becomes $11,000 after year one, then $12,100 after year two (10% of $11,000), and so on. This compounding effect means small differences in CAGR create large differences in final wealth over long periods.

CAGR uses the mathematical relationship between starting value, ending value, and time to reverse-engineer what constant growth rate would connect these points. The formula raises the ratio of ending to starting value to the power of one divided by years, then subtracts one to convert to a percentage.

Use CAGR when comparing investments or business metrics over different time periods. A stock that gained 50% over two years (22.5% CAGR) can be directly compared to one that gained 100% over four years (18.9% CAGR), revealing the first was actually superior despite the smaller absolute gain.

CAGR works well for evaluating business growth, property appreciation, or any metric that compounds over time. Sales revenue, customer count, or asset values all benefit from CAGR analysis because they typically grow on their existing base rather than linearly.

Avoid CAGR for investments with regular contributions like 401k accounts, volatile short-term periods under two years, or when you need to understand the variability of returns rather than just the average. For retirement planning or risk assessment, standard deviation and maximum drawdown provide insights that CAGR alone cannot capture.

The most common mistake is using CAGR when additional money was added or withdrawn during the period. CAGR assumes no cash flows except the initial investment, so adding $5,000 yearly to a retirement account will artificially inflate the calculated growth rate. For investments with regular contributions, use time-weighted return or internal rate of return instead.

Another error is comparing short-term CAGR to long-term benchmarks. A 25% CAGR over two years might seem excellent compared to the stock market's historical 10%, but short periods can be heavily influenced by luck or market timing rather than sustainable performance.

People also mistakenly assume CAGR predicts future performance. A stock with 30% CAGR over five years is not guaranteed to continue growing at that rate. High CAGRs often reflect early-stage growth that naturally slows as companies or investments mature and face increasing competition or market saturation.

The CAGR formula is: CAGR = (Ending Value / Starting Value)^(1/Years) - 1. The exponent (1/Years) is the mathematical key that annualizes the growth rate. When you raise a number to the power of 1/n, you are finding the nth root, which extracts the per-period growth rate from the total growth.

For example, if an investment triples over 6 years, the total growth is 3x, but the annual growth rate is the 6th root of 3, which equals about 1.2 or 20% per year. This root extraction ensures that compounding 20% for 6 years recreates the original 3x total growth.

The subtraction of 1 at the end converts from a multiplier (like 1.2) to a growth rate (like 0.2 or 20%). Financial professionals often work with growth multipliers internally but present results as familiar percentage growth rates to clients.

Professional investors recognize that CAGR masks sequence risk - the order of returns matters even when CAGR is identical. Two investments with 10% CAGR over 10 years could have vastly different risk profiles if one had steady 10% annual returns while another swung between +50% and -30% years.