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Percentage calculator

Solve percentage, part, whole, increase, decrease, reverse change, difference and error.

Get started

  1. For a part such as 15% of 240, choose Percentage of a value. If the part is 36 and you know the total or the rate, choose the corresponding inverse mode.
  2. Choose Percentage change for an ordered old and new value. Use Percentage difference for two positive values with no baseline.
  3. Enter 15 for 15%. Compare the result against the worked examples below.

Example

Input

15% of 240

Expected result

36

Try it

Good to know

The calculation runs in your browser. Use consistent units in fields with no explicit unit.

Calculation method

Percentage = part ÷ whole × 100. Change uses the absolute original value as its denominator. Symmetric difference uses the mean of the absolute values.

x=yp/100,p=100x/y,y=100x/px=yp/100,\quad p=100x/y,\quad y=100x/p
Δ%=100x1−x0∣x0∣,D%=200∣x1−x0∣∣x1∣+∣x0∣\Delta\%=100\frac{x_1-x_0}{|x_0|},\quad D\%=200\frac{|x_1-x_0|}{|x_1|+|x_0|}

80 → 100 is a 25% change because 80 is the starting value. The percentage difference between the same numbers is about 22.22% because the denominator is their mean, 90.

After a 20% increase to 120, Reverse a change gives 100. A change of −100% cannot be reversed. Change from a zero baseline has no percentage result.

For a measured value of 90 and reference of 96, absolute percent error is 6.25%. The signed result with that positive reference is −6.25%.

Calculation mode

Percentage of a value
  • Percentage · %
  • Value
Find the percentage
  • Part
  • Whole
Find the whole
  • Part
  • Percentage · %
Percentage change
  • Original value
  • New value
Percentage difference
  • First value
  • Second value
Difference with signed values
  • First value
  • Second value
Apply a change
  • Original value
  • Signed change · %
Reverse a change
  • New value
  • Signed change · %
Percent error
  • Measured value
  • Reference value
  • Error convention · Absolute / Signed relative to reference