Calculate percent difference between two values and see the formula used for the comparison.
Percentage change, discounts, tax, tips and everyday percent-of-number questions.
Enter two values. The calculator shows their absolute difference, average magnitude and percent difference. The order does not matter because neither value is treated as the starting baseline.
For 80 and 100, the absolute difference is 20, the average magnitude is 90 and the percent difference is about 22.22%.
Use percent difference for two peer values. Use percentage change when one number is clearly the original value and the other is the new value. For directional examples, see percentage increase and percentage decrease.
For measurements 80 and 100, the absolute difference is 20. Their average magnitude is (80 + 100) ÷ 2 = 90, so percent difference is 20 ÷ 90 × 100 = 22.22%.
Different from percent change: swapping 80 and 100 does not change percent difference, but it changes the direction of percent change. Use percent change when you have a clear “before” value; use percent difference for two peer measurements.
No. The absolute difference and average make the formula symmetric.
Percent difference compares two values without treating either one as the original or reference value. For old-versus-new change, use the Percentage Change Calculator.
See how formulas, sources and limitations are handled across ERICH Calculators.