Find Out What Each Dose Really Costs
Compare supplements by what a real dose costs, not by the price on the bottle.
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.
A bigger bottle is not always better value, and a cheaper bottle is not always cheaper per dose. This calculator works out what one dose costs, and what it costs per day and per month, so you can compare two products fairly.
Enter the price, how many servings the container holds, and how many servings you take a day.
One division, three numbers
Cost per serving = price ÷ servings per container
Add servings per day and you also get cost per day, which is cost per serving times servings per day, and cost per month, which is cost per day times 30.
A container priced at 24.99 with 60 servings costs about 0.42 per serving. At 2 servings a day that is about 0.83 per day and about 25 per month. The tool uses plain arithmetic with no outside data, so the result is exact for the numbers you enter.
Why per dose beats per bottle
Cost per dose removes the effect of bottle size and serving count. A large, cheap-looking bottle with a small serving count can cost more per dose than a smaller one.
The monthly figure uses a 30 day month as a round estimate, so treat it as a guide for comparing, not a bill.
Make sure a serving means the same thing
This compares price only. It does not judge quality, ingredient amount, or how well a product is absorbed, and one product's serving may contain more of the active ingredient than another's.
Check the amount per serving first. For herbal products, the Extract Strength Calculator shows the real active amount, and Study Dose vs Product Dose compares a serving with the dose used in research. The Daily Value (%DV) Calculator shows how a serving compares with the daily reference.
Cheapest per dose is not always the best choice, since a higher dose or a better form can be worth more.
Compare like with like
If two labels use different units, switch them with the Serving Size Converter first. For powders, the Scoop to Grams Converter gives the real weight of a scoop, and the Powder to Capsule Converter shows how many capsules the same dose would take, so you can price both forms.
To see how long a bottle will last and when to reorder, try the Bottle Duration Calculator.
Where servings come from
Serving size and servings per container are set by government labeling rules. See the Dietary Supplement Labeling Guide, Chapter IV from the FDA.
The regulation itself is 21 CFR 101.36, nutrition labeling of dietary supplements.
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.