Sumwise

Percentage Change from 15 to 30

From 15 to 30 is a 100% increase

Change
100%
Difference
15
New ÷ old
2
Direction
increase

Sumwise · Maintained by Theo Abbott (pen name) · automated checks · Data: exact arithmetic; unit definitions from NIST SP 811 · Updated · How the checks work

How to work it out

  1. Difference: 30 − 15 = 15
  2. Divide by the starting value: 15 ÷ 15 = 1
  3. Multiply by 100: 100%
  4. Check: Work forwards from the start: 15 × (1 + 1) = 15 × 2 = 30.

In a spreadsheet: =(30-15)/15*100. Always divide by the starting value, not the new one. A rise from 40 to 50 is +25%, but the fall from 50 back to 40 is −20%.

What the result means

The new value is 2 times the old one: for every 100 at the start there are now 200. The value has more than doubled.

Prices: an item whose price rises from $15 to $30 has gone up by 100%.

Why the change back is different

A 100% rise followed by a 100% fall does not bring you back to 15: it gives 0. The second percentage is taken of 30, not of 15, so to undo this change you need 50% instead.

Related results

Results for nearby numbers
15 to 28

From 15 to 28 is a 86.6667% increase

15 to 29

From 15 to 29 is a 93.3333% increase

15 to 31

From 15 to 31 is a 106.6667% increase

15 to 32

From 15 to 32 is a 113.3333% increase

15 to 40

From 15 to 40 is a 166.6667% increase

The other way round: Percentage change from 30 to 15. Percentage change is not symmetric: from 15 to 30 is 100%, but from 30 back to 15 is -50%, because the starting value is the base. For a comparison that is the same both ways, use the percentage difference between 15 and 30: 66.6667%. See Percentage difference between 15 and 30.

Practice

3 to 70
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From 3 to 70 is a 2,233.3333% increase

35 to 24
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From 35 to 24 is a 31.4286% decrease

99 to 40
Show answer

From 99 to 40 is a 59.596% decrease

67 to 51
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From 67 to 51 is a 23.8806% decrease

23 to 34
Show answer

From 23 to 34 is a 47.8261% increase

62 to 7
Show answer

From 62 to 7 is a 88.7097% decrease

Calculate another

How answers are calculated and checked: methodology.

Questions

Percentage Change from 15 to 30

Going from 15 to 30 is a 100% increase. Formula and steps.

Is going from 15 to 30 an increase or a decrease?

An increase: the value grew by 15, which is 100% of the starting value.

What is the percentage change from 30 back to 15?

-50%. It is a different number because the starting value is now 30, not 15.