See How Your Supplement Compares to the Daily Value
Pick a nutrient, type the amount, and get the percent in one click.
This tool was built by Serge (MSc) using established science and government sources. My academic background covers plant biology, environmental biology, and biogeochemistry. My tools are for educational purposes and give practical guidance, not professional advice.
The %DV on a label compares one serving with a fixed reference amount. Pick a nutrient, enter the amount from your supplement, and the calculator returns the percentage of the FDA Daily Value.
It uses the current Daily Values for adults and children aged 4 and over.
The one-line formula
%DV = amount in the serving ÷ Daily Value × 100
A supplement with 500 mg of vitamin C, against a Daily Value of 90 mg, works out to 500 ÷ 90 × 100, or about 556%.
What a big number does and does not mean
A %DV of 100 means one serving gives the full reference amount. Many supplements list several hundred percent, which is common and often fine for water-soluble vitamins.
It deserves a closer look for nutrients that have an upper limit, such as some minerals and fat-soluble vitamins. The Daily Value is one reference number for everyone, not a personal target, so your own needs may be higher or lower.
Get the unit right first
Mixing mg and mcg gives a wrong answer by a factor of 1,000. If your label uses a different unit, the Serving Size Converter switches it first, and the Vitamin Unit Converter handles IU for vitamins A, D, and E.
For minerals, enter the elemental amount. The Elemental Mineral Calculator finds it when a label lists only the compound.
Go one step further
This tool does not count the nutrient you get from food. The Nutrient Gap Estimator looks at where an eating pattern may commonly fall short, so you can see whether a supplement fills a gap.
If several products share a nutrient, the Upper Limit Checker adds them up against the published limit. To see what each serving costs, use the Cost Per Dose Calculator.
Where the Daily Values come from
The reference amounts are the ones the FDA sets for labels: Daily Values for adults and children 4 and over.
The NIH Office of Dietary Supplements explains how to read them: Daily Values explained.
This calculator is for general education only and is not medical or professional advice. Always check product labels and speak with a qualified professional before making decisions about supplements.