## Percentage change calculation and method with example

The percentage change from old value (V_{old}) to new value (V_{new}) is equal to the old and new values difference divided by the old value times 100%:

percentage change = (*V*_{new} - *V*_{old}) / *V*_{old} × 100%

#### Example #1

Price percentage increase from old value of $1000 to new value of $1200 is caluclated by:

percentage change = ($1200 - $1000) / $1000 × 100%

= 0.2 × 100% = 20%

#### Example #2

Price percentage decrease from old value of $1000 to new value of $800 is caluclated by:

percentage change = ($800 - $1000) / $1000 × 100%

= -0.2 × 100% = -20%