What is my year over year growth?
Type a value for last year and the same value for this year. The year over year growth calculator gives the growth in percent and the change in units, the way a YoY calculator reports it.
- Year over year growth
- 15%
From 2,500,000 to 2,875,000 is a change of 15% year over year.
- Change
- 375,000
- Growth or decline
- Growth
Year over year growth: 15%. From 2,500,000 to 2,875,000 is a change of 15% year over year.
How to calculate
Finds year over year growth in percent from a value last year and the same value this year, with the change in units.
Example with the default inputs (Last year 2,500,000, This year 2,875,000): From 2,500,000 to 2,875,000 is a change of 15% year over year.
Method: Growth = (this year − last year) ÷ |last year| × 100.
- Growth is measured against the size of last year’s value, so a rise from −50 to 25 is +150%.
- Last year’s value must not be 0.
- Both values cover the same length of time, such as the same quarter one year apart.
Worked examples
Each example is checked against the calculator on every build.
- Last year 2,500,000, This year 2,875,000 gives Year over year growth 15%, Change 375,000, Growth or decline Growth.Source: OpenStax, Elementary Algebra 2e, section 3.2 Solve Percent Applications (percent increase and percent decrease: the change as a percent of the original amount; $26 to $36 is 38.5%, $3.71 to $3.64 is 1.9%), https://openstax.org/books/elementary-algebra-2e/pages/3-2-solve-percent-applications (retrieved 2026-11-01)
- Last year 26, This year 36 gives Year over year growth 38.46%, Change 10, Growth or decline Growth.Source: OpenStax, Elementary Algebra 2e, section 3.2 Solve Percent Applications (percent increase and percent decrease: the change as a percent of the original amount; $26 to $36 is 38.5%, $3.71 to $3.64 is 1.9%), https://openstax.org/books/elementary-algebra-2e/pages/3-2-solve-percent-applications (retrieved 2026-11-01)
- Last year 3.71, This year 3.64 gives Year over year growth −1.89%, Change -0.07, Growth or decline Decline.Source: OpenStax, Elementary Algebra 2e, section 3.2 Solve Percent Applications (percent increase and percent decrease: the change as a percent of the original amount; $26 to $36 is 38.5%, $3.71 to $3.64 is 1.9%), https://openstax.org/books/elementary-algebra-2e/pages/3-2-solve-percent-applications (retrieved 2026-11-01)
- Last year -50, This year 25 gives Year over year growth 150%, Change 75, Growth or decline Growth.Source: OpenStax, Elementary Algebra 2e, section 3.2 Solve Percent Applications (percent increase and percent decrease: the change as a percent of the original amount; $26 to $36 is 38.5%, $3.71 to $3.64 is 1.9%), https://openstax.org/books/elementary-algebra-2e/pages/3-2-solve-percent-applications (retrieved 2026-11-01)
- Last year 80, This year 80 gives Year over year growth 0%, Change 0, Growth or decline No change.Source: OpenStax, Elementary Algebra 2e, section 3.2 Solve Percent Applications (percent increase and percent decrease: the change as a percent of the original amount; $26 to $36 is 38.5%, $3.71 to $3.64 is 1.9%), https://openstax.org/books/elementary-algebra-2e/pages/3-2-solve-percent-applications (retrieved 2026-11-01)
How it works
This is the percentage change calculator with two periods and growth in percent. With A for last year and B for this year:
- Year over year growth = (B − A) ÷ |A| × 100
- Change = B − A
- Growth or decline is the text Growth when B is above A, Decline when B is below A, and No change when they are equal.
Rules
- The arithmetic is exact on the decimals as typed. The result is rounded once, for display: growth to at most 2 decimals, half up.
- When A is 0 there is no answer, with the message "Last year’s value cannot be 0: growth is measured against it."
- When a result is too large or too small for the page to show (it would be infinite, or a non-zero value would become 0), there is no answer, with the message "A result is too large or too small to show. Scale both values first."
- Both values can be negative. The change is always measured against the size of A.
Worked examples by hand
$2,500,000 to $2,875,000. Change 375,000; 375,000 ÷ 2,500,000 × 100 = 15%, Growth.
$26 to $36. Change 10; 10 ÷ 26 × 100 = 38.46%, Growth.
$3.71 to $3.64. Change −0.07; −0.07 ÷ 3.71 × 100 = −1.89%, Decline.
−50 to 25. Change 75; 75 ÷ |−50| × 100 = 150%, Growth.
80 to 80. Change 0: 0%, No change.
Other questions people ask
How do you calculate year over year growth?
Subtract last year from this year, divide by last year, and multiply by 100. Sales of $2,500,000 last year and $2,875,000 this year grew by 375,000 ÷ 2,500,000 × 100 = 15%.
What does YoY mean?
YoY is short for year over year. It compares a period with the same period one year earlier, such as March with last March, or the third quarter with last year’s third quarter.
Why compare with the same period last year?
It takes out regular seasonal swings. A shop that always sells more in December would look like it was growing every December if you compared it with November.
What if the growth is negative?
The value fell. Going from 3.71 to 3.64 is a change of −0.07, which is −1.89% year over year. The page says Decline.
What if last year was 0 or negative?
From 0 there is no growth rate, because the change would be divided by 0, so the page gives no answer. From a negative value, the change is measured against its size: −50 to 25 is a change of 75, and 75 ÷ 50 is +150%. Read that figure with care, since it means a loss turned into a profit.
Is this the same as compound annual growth?
Over exactly one year, yes. Over several years, year over year gives one number for each pair of years, while a compound rate gives one average rate for the whole span.