REVERSE PERCENTAGE
Find the ORIGINAL value before an increase/decrease
Example: £72 after +20% → original = £60 • NO SCROLL
KNOWN VALUE
VALUE
The value you have (after change)
PERCENT
%
Enter 20 for 20%
TYPE
INC
Choose what KNOWN VALUE represents
ROUNDING
2DP
Result rounding only
WORKING
—
—
—
—
—
ORIGINAL
READY
—
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KNOWN VALUE
VALUE
The value you have (after change)
PERCENT
%
Enter 20 for 20%
TYPE
INC
Choose what KNOWN VALUE represents
ROUNDING
2DP
Result rounding only
WORKING
—
—
—
—
—
ORIGINAL
READY
—
PAGE 1/2
IDEA
Known value is the FINAL value
We undo the percentage change
final = original × multiplier
MULTIPLIERS
+p% ⇒ multiplier = 1 + p/100
−p% ⇒ multiplier = 1 − p/100
p% of original ⇒ multiplier = p/100
FORMULA
original = final ÷ multiplier
Then round using the rounding setting
WORKED EXAMPLES
£72 after +20%:
mult=1.2 → orig=72÷1.2=60
£45 after −10%:
mult=0.9 → orig=45÷0.9=50
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