Growth Rate Calculator
Enter a starting value, ending value, and number of periods. The calculator returns total growth, average growth per period, and annualized growth.
What is the formula for calculating growth rate?
The most common growth rate formula is:
To convert that decimal into a percentage, multiply by 100:
This formula tells you how much something has increased or decreased relative to where it started. You can use it for revenue, users, investments, population, production output, website traffic, and more.
Three growth formulas you should know
1) Total growth over a period
Use this when you only care about the net change from start to finish.
- Great for quick reports and headline numbers.
- Does not show how smooth or volatile growth was during the period.
2) Average periodic growth (geometric)
If growth happens across multiple periods (months, quarters, years), the geometric average is more accurate than a simple arithmetic average.
Where n is the number of periods.
3) CAGR (Compound Annual Growth Rate)
CAGR is the annualized growth rate. It smooths growth into a single yearly rate as if growth were steady.
Investors and business analysts use CAGR constantly because it allows apples-to-apples comparison across different time horizons.
Worked example
Suppose a business grows from $50,000 to $80,000 in 4 years.
- Total growth: (80,000 - 50,000) / 50,000 = 0.60 = 60%
- CAGR: (80,000 / 50,000)^(1/4) - 1 ≈ 0.1247 = 12.47% per year
Total growth says “up 60% overall.” CAGR says “equivalent to about 12.47% each year, compounded.”
When to use each formula
- Use total growth for quick before-and-after comparisons.
- Use periodic growth when analyzing month-over-month or quarter-over-quarter change.
- Use CAGR when comparing investments, companies, or strategies over different lengths of time.
Common mistakes to avoid
Using the wrong base value
The denominator should almost always be the starting value for the period you are measuring.
Mixing period types
If your data is monthly, keep periods in months—or explicitly annualize at the end.
Ignoring negative or zero start values
If the starting value is zero, percentage growth is undefined (division by zero). For geometric growth and CAGR, both start and end values should be positive.
Using arithmetic average instead of compounded average
In multi-period growth analysis, geometric averaging is usually the correct method because it respects compounding.
Quick interpretation guide
- Positive growth rate: value increased.
- Negative growth rate: value decreased.
- 0% growth: no change.
- Higher CAGR: stronger long-term compounding.
Bottom line
The core formula for calculating growth rate is simple: subtract old from new, divide by old, then convert to a percentage. For multi-period analysis, use compounded formulas like average periodic growth and CAGR to get a clearer and more realistic picture. Use the calculator above to run both instantly.