Percent Change

Also known as percent increase · percent decrease

c=xnewxoldxoldc = \frac{x_{\text{new}} - x_{\text{old}}}{x_{\text{old}}}

Enter your known values, leave one input blank, and solves for the missing one. Try different units for next level excitement!

Learning zone

Percent change measures a difference relative to where you started: a price moving from $80 to $92 changed by (92 − 80)/80 = 0.15, a 15% rise; a fall from $80 to $68 gives −0.15. Pick the % display unit to see it as a percentage directly, and note that the old value is always the reference — which is why a 50% loss needs a 100% gain to break even.

The rearrangements handle both everyday directions: what a $60 jacket costs after a 30% markup (60 × 1.30 = $78), and the reverse — the pre-sale price of an item now $45 after a 25% discount, 45 / 0.75 = $60, not $56.25 as adding 25% back would wrongly suggest.

Percent Change
c=xnewxoldxoldc = \frac{x_{\text{new}} - x_{\text{old}}}{x_{\text{old}}}
Where
  • cc= Relative change
  • xnewx_{\text{new}}= New value
  • xoldx_{\text{old}}= Old value
Missing one of these? Work it out first, then come back