Math & Statistics · Browser · Free

Percentage Change Calculator

Compare an old value with a new value to get the percentage change and the difference, or switch the calculation to find the new value that an old value becomes after a given percentage change.

What this calculator does

The tool works with an old value and a new value. Choose Percentage change to see how far the value moved as a percentage, or choose New value to see what the old value becomes after a given percentage change.

Enter Old value together with New value or Percentage change, then press Calculate. Nothing is worked out before you press it. The results show up in cards below the button, where Copy puts a result and its unit on the clipboard and Clear resets the form.

Percentage change formula

The percentage change is the difference between the new value and the old value, divided by the old value, times 100%: p = (Vnew - Vold) / Vold × 100%.

An old value of 1000 and a new value of 1200 give a percentage change of 20 % and a difference of 200. When the new value is smaller than the old value the change is negative: from 1000 to 900 the change is -10 % and the difference is -100.

A change from 3 to 7 is about 133.333333333333 %, with a difference of 4.

New value formula

The difference is the old value times the percentage change divided by 100: d = Vold × p / 100. The new value is the old value plus that difference, which is the same as Vnew = Vold × (1 + p / 100).

So an old value of 1000 with a percentage change of 20 gives a new value of 1200 and a difference of 200, while a percentage change of -10 gives a new value of 900 and a difference of -100.