Sumwise

Percentage Change from 42 to 30

From 42 to 30 is a 28.5714% decrease

Change
-28.5714%
Difference
-12
New ÷ old
0.714286
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: 30 − 42 = -12
  2. Divide by the starting value: -12 ÷ 42 = -0.285714
  3. Multiply by 100: -28.5714%
  4. Check: Work forwards from the start: 42 × (1 − 0.285714) = 42 × 0.714286 = 30.

In a spreadsheet: =(30-42)/42*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 71.4286% of the old one: for every 100 at the start there are now 71.4286, so 28.5714 out of every 100 have gone.

Sales: a price cut from $42 to $30 is a 28.5714% discount.

Why the change back is different

A 28.5714% fall followed by a 28.5714% rise does not bring you back to 42: it gives 38.5714. The second percentage is taken of 30, not of 42, so to undo this change you need 40% instead.

Related results

Results for nearby numbers
42 to 28

From 42 to 28 is a 33.3333% decrease

42 to 29

From 42 to 29 is a 30.9524% decrease

42 to 31

From 42 to 31 is a 26.1905% decrease

42 to 32

From 42 to 32 is a 23.8095% decrease

42 to 40

From 42 to 40 is a 4.7619% decrease

The other way round: Percentage change from 30 to 42. Percentage change is not symmetric: from 42 to 30 is -28.5714%, but from 30 back to 42 is 40%, because the starting value is the base. For a comparison that is the same both ways, use the percentage difference between 30 and 42: 33.3333%. See Percentage difference between 30 and 42.

Practice

8 to 97
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From 8 to 97 is a 1,112.5% increase

55 to 39
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From 55 to 39 is a 29.0909% decrease

65 to 57
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From 65 to 57 is a 12.3077% decrease

30 to 90
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From 30 to 90 is a 200% increase

24 to 27
Show answer

From 24 to 27 is a 12.5% increase

34 to 23
Show answer

From 34 to 23 is a 32.3529% decrease

Calculate another

How answers are calculated and checked: methodology.

Questions

Percentage Change from 42 to 30

Going from 42 to 30 is a 28.5714% decrease. Formula and steps.

Is going from 42 to 30 an increase or a decrease?

A decrease: the value fell by 12, which is 28.5714% of the starting value.

What is the percentage change from 30 back to 42?

40%. It is a different number because the starting value is now 30, not 42.