Type of calculation: Calculating percentage decrease.
How to use the calculator: First, find your new weight (
80 lb -
8 lb =
72 lb). Then use the
Percentage Change CALCULATOR ("What is the percentage change from the Original value to the New value?"). Enter the starting weight
80 [Original] and the new weight
72 [New]. It will calculate the drop.
The formula:
First, let's get the new weight:
New weight = Old weight - Weight lost
New weight =
80 lb -
8 lb =
72 lb
Now, find the percentage change from
80 lb to
72 lb.
Formula: ((New weight - Old weight) / Old weight) × 100%
Percentage change = ((
72 -
80) /
80) × 100% = (
-8 /
80) × 100% =
-0.1 × 100%
= -10% (minus means weight loss)
Another way (using "Part-to-Whole Percentage CALCULATOR"): You can simply check what percentage
8 lb (lost) is out of
80 lb (starting weight). Use the
Part-to-Whole Percentage CALCULATOR ("What percentage of Y is Z?"). Enter
80 [Y] and
8 [Z]. You get
10%. Since it's a loss, that's a
10% decrease.