Sumwise

What is the Percentage Difference from 15 to 21?

From 15 to 21 is a 40% increase

Change
40%
Difference
6
New ÷ old
1.4
Direction
increase

Sumwise · Data: exact arithmetic; unit definitions from NIST SP 811 · Updated · How we check it

How to work it out

  1. Difference: 21 − 15 = 6
  2. Divide by the starting value: 6 ÷ 15 = 0.4
  3. Multiply by 100: 40%
  4. Check: Work forwards from the start: 15 × (1 + 0.4) = 15 × 1.4 = 21.

In a spreadsheet: =(21-15)/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 1.4 times the old one: for every 100 at the start there are now 140.

Prices: an item whose price rises from $15 to $21 has gone up by 40%.

Why the change back is different

A 40% rise followed by a 40% fall does not bring you back to 15: it gives 12.6. The second percentage is taken of 21, not of 15, so to undo this change you need 28.5714% instead.

Related results

Results for nearby numbers
15 to 19

From 15 to 19 is a 26.6667% increase

15 to 20

From 15 to 20 is a 33.3333% increase

15 to 22

From 15 to 22 is a 46.6667% increase

15 to 23

From 15 to 23 is a 53.3333% increase

15 to 31

From 15 to 31 is a 106.6667% increase

The other way round: Percentage difference from 21 to 15

Practice

3 to 59
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From 3 to 59 is a 1,866.6667% increase

39 to 65
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From 39 to 65 is a 66.6667% increase

48 to 9
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From 48 to 9 is a 81.25% decrease

45 to 30
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From 45 to 30 is a 33.3333% decrease

56 to 54
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From 56 to 54 is a 3.5714% decrease

12 to 29
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From 12 to 29 is a 141.6667% increase

Calculate another

How answers are calculated and checked: methodology.

Questions

What is the Percentage Difference from 15 to 21?

Going from 15 to 21 is a 40% increase. Formula and steps.

Is going from 15 to 21 an increase or a decrease?

An increase: the value grew by 6, which is 40% of the starting value.

What is the percentage change from 21 back to 15?

-28.5714%. It is a different number because the starting value is now 21, not 15.