Percentage Change Calculator

The starting value for a change, the accepted (true) value for percent error.
The ending value for a change, the measured (experimental) value for percent error.
Used by the improvement comparison only. Cutting a 50 ms response time to 40 ms is a 20% improvement even though the number went down.
Answer for the selected comparison
50 %
Percentage Change, Difference and Error Calculator
What the answer is
Percentage change
In words
50 to 75 is a change of 50% (increase).
Percentage change
50 %
Percentage increase
50 %
Percentage decrease
-50 %
Absolute change (final - initial)
25
Percentage difference
40 %
Percent improvement
50 %
Percent error
50 %
Relative error (a fraction, not a percentage)
0.5
Final / initial
1.5
Direction
increase
Formula used
percent change = (final - initial) / |initial| x 100
Worked out from Wikipedia, "Relative change and difference" — relative change uses |x_reference| in the denominator; percentage difference uses the mean of the magnitudes and 1 other source.

How this is worked out

3 steps
  1. Change = 75 - 50 = 25
  2. Divide by the size of the starting value: 25 / 50 = 0.5
  3. Multiply by 100: 50% (increase)

Results are general information, not financial, tax, legal, medical or engineering advice.