Sumwise

Percentage Change from 40 to 30

From 40 to 30 is a 25% decrease

Change
-25%
Difference
-10
New ÷ old
0.75
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 − 40 = -10
  2. Divide by the starting value: -10 ÷ 40 = -0.25
  3. Multiply by 100: -25%
  4. Check: Work forwards from the start: 40 × (1 − 0.25) = 40 × 0.75 = 30.

In a spreadsheet: =(30-40)/40*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 75% of the old one: for every 100 at the start there are now 75, so 25 out of every 100 have gone.

Sales: a price cut from $40 to $30 is a 25% discount.

Why the change back is different

A 25% fall followed by a 25% rise does not bring you back to 40: it gives 37.5. The second percentage is taken of 30, not of 40, so to undo this change you need 33.3333% instead.

Related results

Results for nearby numbers
40 to 28

From 40 to 28 is a 30% decrease

40 to 29

From 40 to 29 is a 27.5% decrease

40 to 31

From 40 to 31 is a 22.5% decrease

40 to 32

From 40 to 32 is a 20% decrease

The other way round: Percentage change from 30 to 40. Percentage change is not symmetric: from 40 to 30 is -25%, but from 30 back to 40 is 33.3333%, because the starting value is the base. For a comparison that is the same both ways, use the percentage difference between 30 and 40: 28.5714%. See Percentage difference between 30 and 40.

Practice

8 to 99
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From 8 to 99 is a 1,137.5% increase

19 to 22
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From 19 to 22 is a 15.7895% increase

7 to 86
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From 7 to 86 is a 1,128.5714% increase

21 to 85
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From 21 to 85 is a 304.7619% increase

88 to 25
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From 88 to 25 is a 71.5909% decrease

61 to 83
Show answer

From 61 to 83 is a 36.0656% increase

Calculate another

How answers are calculated and checked: methodology.

Questions

Percentage Change from 40 to 30

Going from 40 to 30 is a 25% decrease. Formula and steps.

Is going from 40 to 30 an increase or a decrease?

A decrease: the value fell by 10, which is 25% of the starting value.

What is the percentage change from 30 back to 40?

33.3333%. It is a different number because the starting value is now 30, not 40.