Calculate percentage decrease
| Cell | Meaning | Example value |
|---|---|---|
| A2 | Old value | 100 |
| B2 | New value | 80 |
Formula
=(A2-B2)/ABS(A2)Expected result: 20%
Format the result cell as a percentage. The old value in A2 cannot be zero.
Percentage Decrease Calculator
Find the percent reduction from an original value to a lower new value, using the original value as the reference.
Percentage Decrease Calculator
Decrease from to =
How it works
Formula and steps
The formula shows how the percentage decrease calculator turns your inputs into the result. Use it to check the calculation, then follow the example steps to see each part of the math.
Formula & steps
Percentage decrease formula
D% = ((OV - NV) / |OV|) x 100
Use this when the new value is lower than the old value.
D%= Percentage decreaseOV= Old valueNV= New value|OV|= Absolute old value- 1100 - 80 = 20
- 220 / 100 = 0.2
- 30.2 x 100 = 20% decrease
Worked examples
Example 1
Monthly costs fall from $2,500 to $2,200
- 1
Find the decrease
$2,500 - $2,200 = $300
- 2
Divide by the original cost
$300 / $2,500 = 0.12
- 3
Convert to a percent
0.12 x 100 = 12% decrease
Example 2
A price falls from $120 to $90
- 1
Find the decrease
$120 - $90 = $30
- 2
Divide by the original price
$30 / $120 = 0.25
- 3
Convert to a percent
0.25 x 100 = 25% decrease
Spreadsheet formulas
Calculate in Excel or Google Sheets
Enter the example values in the listed cells, then paste the formula into another cell. Excel and Google Sheets use the same formulas shown here.
Common uses
- Cost and expense reductions
- Price drops
- Traffic or performance declines
- Inventory shrinkage
Common mistakes
- Dividing by the new value instead of the original value.
- Subtracting the discount rate from a value without first converting it to a decimal.
- Calling a drop from zero a percentage decrease; division by the original zero value is undefined.
Percentage decrease guide
How to calculate percentage decrease
Percentage decrease measures a reduction relative to the original value. The original value remains the denominator even after the value falls.
Calculate a percent reduction
Subtract the lower new value from the original value, divide the decrease by the absolute original value, and multiply by 100. A fall from 120 to 90 is a 25% decrease.
Decrease versus discount
Percentage decrease compares an observed old value with a lower new value. A discount calculation starts with a listed percent off and finds the savings and sale price.
Calculate a discount and sale price →Use percentage change when direction is unknown
If the new value could be above or below the old value, percentage change uses a positive sign for growth and a negative sign for decline.
Calculate percentage change →FAQ
Subtract the new value from the old value, divide by the old value, then multiply by 100.
Multiply the original value by 20 / 100 to find the decrease amount, then subtract it from the original value.
For ordinary nonnegative quantities, a fall to zero is a 100% decrease and the value cannot fall further. Signed values can produce less intuitive results.
Percentage decrease from zero is undefined because the formula divides by the original value. Use the numerical difference instead.
This calculator uses the absolute original value as the denominator. Results involving negative values or a move across zero may not match ordinary price or quantity interpretations, so report the original and new values too.
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