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What is the Percentage Difference from 21 to 11?

From 21 to 11 is a 47.619% decrease

Step by step

  1. Difference: 11 − 21 = -10
  2. Divide by the starting value: -10 ÷ 21 = -0.47619
  3. Multiply by 100: -47.619%

How the answer is worked out

Percentage change measures a difference against the value you started with. The value went from 21 to 11, a difference of 10. Compared with the starting value of 21, that difference is 47.619%, so this is a 47.619% decrease.

The new value is 52.381% of the old one: for every 100 at the start there are now 52.381, so 47.619 out of every 100 have gone.

Why calculate this?

Percentage change compares a new value with an old one regardless of size: price rises, growth, discounts, score changes.

  • Sales: a price cut from $21 to $11 is a 47.619% discount.
  • Weight: going from 21 to 11 kilograms is a loss of 47.619% of the starting weight.
  • Results: if a team scores 11 points this season after 21 last season, its total has dropped by 47.619%.

A quicker way

Find 1% of the starting value: 21 ÷ 100 = 0.21. The difference of 10 is 47.619 of those steps.

Percentage change is not the same as percentage points. If a rate moves from 21% to 11%, it changes by 10 percentage points, but by 47.619% relative to where it started.

Check the answer

Work forwards from the start: 21 × (1 − 0.47619) = 21 × 0.52381 = 11. Getting 11 shows the answer is right.

Rounding

Rounded to a whole number the change is -48, to one decimal place -47.6 and to two decimal places -47.62. Round only at the end: rounding halfway through a calculation can change the last digit.

The formula explained

percentage change = (new value − old value) ÷ old value × 100. A positive result is an increase and a negative result is a decrease. The old value is always the base, which is why the change from A to B and from B to A are different percentages.

Another worked example: 4 to 31

  1. Difference: 31 − 4 = 27
  2. Divide by the starting value: 27 ÷ 4 = 6.75
  3. Multiply by 100: 675%

Why the change back is different

A 47.619% fall followed by a 47.619% rise does not bring you back to 21: it gives 16.2381. The second percentage is taken of 11, not of 21, so to undo this change you need 90.9091% instead.

Other ways to ask this

The same calculation is often asked in other words. All of these have the answer above:

  • Percentage decrease from 21 to 11
  • What percent less is 11 than 21?
  • 21 to 11 as a percent change
  • How much did 21 fall going to 11, in percent?
  • Relative change between 21 and 11

Terms used on this page

  • Old value: the starting amount, used as the base of the percentage.
  • New value: the amount after the change.
  • Increase: a positive change: the new value is bigger.
  • Percentage point: the plain difference between two rates, not a relative change.

The answer in other forms

Change-47.619%
Difference-10
New ÷ old0.52381
Directiondecrease

Related results

21 to 9

From 21 to 9 is a 57.1429% decrease

21 to 10

From 21 to 10 is a 52.381% decrease

21 to 12

From 21 to 12 is a 42.8571% decrease

21 to 13

From 21 to 13 is a 38.0952% decrease

The other way round: Percentage difference from 11 to 21

Doing it in a spreadsheet

In Excel, Google Sheets or Numbers type =(11-21)/21*100 into any cell. Replace the numbers with cell references (for example A1 and B1) to reuse the formula for a whole column.

Common mistakes

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%.

Practice examples

4 to 31
Show answer

From 4 to 31 is a 675% increase

44 to 25
Show answer

From 44 to 25 is a 43.1818% decrease

78 to 90
Show answer

From 78 to 90 is a 15.3846% increase

52 to 64
Show answer

From 52 to 64 is a 23.0769% increase

47 to 43
Show answer

From 47 to 43 is a 8.5106% decrease

84 to 47
Show answer

From 84 to 47 is a 44.0476% decrease

51 to 43
Show answer

From 51 to 43 is a 15.6863% decrease

8 to 15
Show answer

From 8 to 15 is a 87.5% increase

44 to 43
Show answer

From 44 to 43 is a 2.2727% decrease

24 to 12
Show answer

From 24 to 12 is a 50% decrease

Calculate another

How this answer was calculated

The result is worked out from the numbers in this page's address when the page is opened, using exact arithmetic wherever possible and rounding only for display. Nothing is copied from a printed table. If you think an answer is wrong, please tell us through the contact page and we will check it.

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Questions

What is the Percentage Difference from 21 to 11?

Going from 21 to 11 is a 47.619% decrease. Formula and steps.

Is going from 21 to 11 an increase or a decrease?

A decrease: the value fell by 10, which is 47.619% of the starting value.

What is the percentage change from 11 back to 21?

90.9091%. It is a different number because the starting value is now 11, not 21.

What is the percentage difference between 21 and 11?

When neither value is the starting point, use the average as the base: 10 ÷ 16 × 100 = 62.5%. That is the symmetric percentage difference.

How do I calculate percentage change in Excel or Google Sheets?

Put the old value in A1 and the new value in B1, then type =(B1-A1)/A1 and format the cell as a percentage. For these numbers it shows -47.619%.