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How to Calculate Percent Change

Whenever you see a sale price (or a price increase), you may want to know how much the price has changed. Knowing the percentage change can help you make an informed purchasing decision.

Calculate Percent Change

  1. 1
    Obtain the original price and the sale price. For the purposes of this tutorial, consider a pair of pants that was $50 last week and is now $30.

  2. 2
    Subtract the higher price by the lower price. In this example, the difference would be $20.

  3. 3
    Determine whether you want the percentage of change of increase or decrease. This is a subtle, yet important, distinction.

    • If you want to know how much the price decreased, divide by the larger number. In this case, the percentage change would be 20 ÷ 50 or 40%.
    • If the pants were $30 and are now $50, and you want to know percentage of increase between this week's price and last week's price, divide by original price. In this case, the percentage change would be 20 ÷ 30 or 67%. See "Tips" next for a more detailed explanation.

Sample Percent Change Calculator

Percent Change Calculator

Tips

  • If the normal price of an item is $50.00 and you bought it on sale for $30.00 then the percentage change is:
    • ($50.00 - $30.00)/$50.00 × 100 = 20/50 × 100 = 40%

      The price you bought it for was less than the original price so this is a percentage decrease of 40 percent. Hence you saved 40% of the original price.
    7 Helpful?  6
  • Now let's consider that you would like to sell the pants you just purchased. For example if you purchased the pants for $30 and later sold them for $50 then the change is $50 - $30 = $20. The starting value was $30 so the percentage change is:
    • ($50.00 - $30.00)/$30.00 × 100 = 20/30 × 100 = 66.7%

      Thus the value of the pants increased by 66.7% of the original price, a 66.7% increase.
    3 Helpful?  4
  • When the pants changed in value from $50 down to $30 they depreciated in value by 40%. When the pants changed in value again from $30 back up to $50 they appreciated in value by 66.7%. However, it's important to note that the profit percentage when the pants were sold for $50 was still only 40% because it is based on the $20 increase unlike the appreciation value.
    1 Helpful?  4
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Featured Articles | Mathematics

Edited by Linus, Teresa, Flickety, Zareen and 20 others

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