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Free online percentage change calculator

Percentage change measures how much a value grew or shrank relative to its starting point. Choose a mode to find the change, the new value, or the original value.

Calculate
Percent change
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Difference
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Direction
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About this calculator

How to use

  1. Pick a mode: % Change (given old and new), New Value (given old and a percent), or Original Value (given new and a percent).
  2. Enter the two known values.
  3. The result, difference, and direction appear immediately.

Formulas

Percentage change (mode: % Change)

% change = ((new − old) / |old|) × 100

New value (mode: New Value)

new = old × (1 + % / 100)

Original value (mode: Original Value)

old = new / (1 + % / 100)

Worked examples

Price drop: a jacket cost $80 and now costs $68. % change = ((68 − 80) / 80) × 100 = −15% (decrease)

Salary raise: starting salary $50,000, raise of 8%. New = 50,000 × 1.08 = $54,000

Reverse calculation: a product sells for $115 after a 15% markup. Original price? Original = 115 / 1.15 = $100

Notes

  • A negative percentage means the value decreased.
  • If the original value is zero, percentage change is mathematically undefined; the calculator shows 0%.
  • Results are rounded to four decimal places.

Frequently asked

How is percentage change calculated?
Percentage change = ((new − old) / |old|) × 100. A positive result is an increase; negative is a decrease.
How do I find the new value after a percentage change?
New value = old × (1 + percent / 100). Example: 200 increased by 15% → 200 × 1.15 = 230.
How do I find the original value if I know the new value and the percentage change?
Original = new / (1 + percent / 100). Example: the result is 230 after a 15% increase → 230 / 1.15 = 200.
What is the difference between percentage change and percentage difference?
Percentage change always compares a new value to a defined starting point. Percentage difference divides by the average of both values and has no directional meaning.
Can the percentage change exceed 100%?
Yes. If a value doubles, the percentage change is 100%. Tripling gives 200%, and so on. There is no upper limit.
What happens when the original value is zero?
Division by zero makes the percentage change undefined. The calculator returns 0% and flags "no change" in that case.

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