Sumwise

Percentage Change from 45 to 9

From 45 to 9 is a 80% decrease

Change
-80%
Difference
-36
New ÷ old
0.2
Direction
decrease

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: 9 − 45 = -36
  2. Divide by the starting value: -36 ÷ 45 = -0.8
  3. Multiply by 100: -80%
  4. Check: Work forwards from the start: 45 × (1 − 0.8) = 45 × 0.2 = 9.

In a spreadsheet: =(9-45)/45*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 20% of the old one: for every 100 at the start there are now 20, so 80 out of every 100 have gone.

Sales: a price cut from $45 to $9 is a 80% discount.

Why the change back is different

A 80% fall followed by a 80% rise does not bring you back to 45: it gives 16.2. The second percentage is taken of 9, not of 45, so to undo this change you need 400% instead.

Related results

Results for nearby numbers
45 to 7

From 45 to 7 is a 84.4444% decrease

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From 45 to 8 is a 82.2222% decrease

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From 45 to 10 is a 77.7778% decrease

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The other way round: Percentage change from 9 to 45. Percentage change is not symmetric: from 45 to 9 is -80%, but from 9 back to 45 is 400%, because the starting value is the base. For a comparison that is the same both ways, use the percentage difference between 9 and 45: 133.3333%. See Percentage difference between 9 and 45.

Practice

9 to 86
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From 9 to 86 is a 855.5556% increase

12 to 82
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From 12 to 82 is a 583.3333% increase

3 to 71
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From 3 to 71 is a 2,266.6667% increase

24 to 76
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From 24 to 76 is a 216.6667% increase

44 to 12
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From 44 to 12 is a 72.7273% decrease

71 to 75
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From 71 to 75 is a 5.6338% increase

Calculate another

How answers are calculated and checked: methodology.

Questions

Percentage Change from 45 to 9

Going from 45 to 9 is a 80% decrease. Formula and steps.

Is going from 45 to 9 an increase or a decrease?

A decrease: the value fell by 36, which is 80% of the starting value.

What is the percentage change from 9 back to 45?

400%. It is a different number because the starting value is now 9, not 45.