A percentage-point difference subtracts two percentages directly. A relative percentage change divides that difference by the starting percentage. Both can be valid, but they communicate different things.
A clear example
Imagine two equal portions listed at 10% DV and 15% DV for the same nutrient. The difference is 5 percentage points. Relative to the 10% starting value, 15% is 50% higher: (15 − 10) ÷ 10 × 100. Calling it a “5% increase” mixes the two methods.
Check the comparison basis
The two percentages must refer to the same nutrient reference and compatible portions. Comparing sodium %DV from one product with fiber %DV from another is not a point difference with a useful dietary meaning. Changing the portion can also change the conclusion.
Prefer the quantity when it is clearer
If both panels give gram or milligram amounts, put those beside the percentages. “An additional 2 g fiber for this portion” can be easier to use than a relative increase. A percentage reference adds context, but it should not conceal how much food or nutrient is involved.
Rounded percentages can make small differences imprecise. If you have the underlying amounts, calculate from those before writing a comparison, then round the result sensibly. FDA’s Daily Value guidance explains what the label percentages refer to. This article’s invented percentage pair is a language and arithmetic example, not a claim about any product or a personalised nutrient target.
Sources and example boundaries
- FDA: Daily Values
Percent Daily Value is a reference comparison, not a personalised target.
All food figures and prices in the worked example are invented to explain the method. They are not restaurant nutrition, tested recipes, shopping prices or personal dietary advice. Use the current label for the product you actually have.