Question 1

How do I calculate percentage change?

Accepted Answer

Percentage Change = ((New Value − Old Value) ÷ |Old Value|) × 100. If the result is positive, it's an increase. If negative, it's a decrease. For example, going from 200 to 250: ((250−200)÷200)×100 = 25% increase.

Question 2

What is the difference between percentage change and percentage difference?

Accepted Answer

Percentage change measures growth or decline relative to the original value (old → new). Percentage difference compares two values without an original reference, using the average as the denominator. Use percentage change for before/after scenarios, and percentage difference when comparing two independent values.

Question 3

How do I calculate percentage increase?

Accepted Answer

Percentage Increase = ((New Value − Old Value) ÷ Old Value) × 100. Example: Salary went from $50,000 to $55,000: ((55000−50000)÷50000)×100 = 10% increase.

Question 4

Can percentage change be more than 100%?

Accepted Answer

Yes, percentage change can exceed 100%. For example, going from 10 to 30 is a 200% increase ((30−10)÷10×100). However, a percentage decrease can never exceed 100% since the value cannot go below zero.

Question 5

What if the old value is zero?

Accepted Answer

When the old value is zero, percentage change is mathematically undefined (division by zero). This represents going from nothing to something, which is conceptually infinite. In practice, you should describe this as 'new value from zero' rather than as a percentage change.

📈 Percentage Change Calculator