Percentage Change Calculator (Advanced) Formula

Understand the math behind the percentage change calculator (advanced). Each variable explained with a worked example.

Use the Percentage Change Calculator (Advanced)

Formulas Used

Pct Change

pct_change = original != 0 ? ((new_val - original) / abs(original)) * 100 : 0

Pct Diff

pct_diff = (original + new_val) != 0 ? abs(new_val - original) / ((abs(original) + abs(new_val)) / 2) * 100 : 0

Abs Change

abs_change = new_val - original

Ratio

ratio = original != 0 ? new_val / original : 0

Variables

VariableDescriptionDefault
originalOriginal Value80
new_valNew Value92

How It Works

Percentage Change vs Percentage Difference

Percentage Change

% Change = ((New - Original) / |Original|) × 100

Used when there is a clear "before" and "after" value.

Percentage Difference

% Difference = |New - Original| / ((|Old| + |New|) / 2) × 100

Used when comparing two values without a clear reference (e.g., comparing two measurements).

Worked Example

A value changed from 80 to 92.

original = 80new_val = 92
  1. 01% Change = (92 - 80)/80 × 100 = 12/80 × 100 = 15%
  2. 02% Difference = 12/86 × 100 ≈ 13.95%
  3. 03Absolute change = 12
  4. 04Ratio = 92/80 = 1.15

Ready to run the numbers?

Open Percentage Change Calculator (Advanced)