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.
Edit Steps
Sample Percent Change Calculator
Calculate Percent Change
- 1Obtain 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.
- 2Subtract the higher price by the lower price. In this example, the difference would be $20.
- 3Determine 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.
Edit 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.
- ($50.00 - $30.00)/$50.00 × 100 = 20/50 × 100 = 40%
- 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.
- ($50.00 - $30.00)/$30.00 × 100 = 20/30 × 100 = 66.7%
- 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.
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Edit Related wikiHows
Edit Sources and References
- Macon State College -- MATH 1101: Calculating Percentage Change
- Math Goodies -- Percent Change
- Wikipedia -- Relative change and difference
- Khan Academy -- Growing by a percentage
- Clemson Phoenix Tutorials -- Physics Tutorial: % Error & % Difference
Article Info
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Categories: Featured Articles | Mathematics
Recent edits by: Tigerflower2, Winterboy, Dr.Ray
