Supplement decision tools
Supplement Cost Calculator
Compare two supplement labels by price per serving and the same ingredient amount. Enter your own prices, even when the bottles use different serving sizes or units.
Quick Answer
A cheaper bottle can cost more for the same amount of an ingredient. Divide the bottle price by its label servings, then adjust for the ingredient amount you want to compare. The calculator converts mg, g and mcg. It compares price, not effectiveness, purity or an amount you should take.
Compare Two Supplements
Use the same ingredient for both products. We convert mg, g and mcg for the price comparison, not for medical equivalence.
Enter your label values, then compare costs.
Have the reviewed NOW 180-tablet bottle? Load its 90 two-tablet servings and 200 mg elemental magnesium per serving into Product A. This does not load a price or recommend an amount to take. Check the retailer pack before entering its price.
Replace Product A with the reviewed NOW 180-tablet label? Its price will be cleared. Product B will stay unchanged.
Find Your Next Comparison
The lowest calculated price is only one part of the decision. Use the guide that matches your ingredient.
Magnesium
Compare elemental amounts, tablet counts and form tradeoffs before choosing.
Compare Magnesium Glycinate Supplements
How To Compare Magnesium LabelsOmega-3
Compare EPA + DHA, not total fish oil. Match the exact bottle and serving size.
Sports Research Vs Nordic Naturals
Find EPA + DHA On The LabelCreatine
A smaller serving or lower price does not establish equal results across forms.
Creatine Monohydrate Vs HCl
Read The Thorne Creatine AnalysisProtein
Compare actual protein grams, not the weight of a scoop. Keep collagen and complete protein separate.
Compare Protein Powder Cost Per Gram
Collagen Vs Protein For Muscle
How To Read Your Result
Start with cost per equal ingredient amount. Cost per serving answers a different question because brands can define a serving differently. If one bottle uses two tablets per serving, do not enter its tablet count as its serving count.
Compare the same ingredient and check the form. For magnesium, use the elemental amount on the magnesium label. For fish oil, use EPA + DHA rather than total fish oil. Different forms, added ingredients, tolerance and testing can still matter after the price calculation.
A price difference is not a quality verdict. Before buying, check what the product’s third-party testing actually covers. A badge alone does not establish that a particular bottle was independently tested.
How This Tool Works
Cost per comparison amount = bottle price x comparison amount / (servings per bottle x active amount per serving). Both ingredient amounts must use the same unit. The tool converts grams and micrograms to a common milligram basis before comparing them.
Use the price and label from the same pack. Include shipping, tax and discounts only if you can apply them consistently to both products. A subscription price and a one-time price are not the same offer. The calculator does not fetch prices, verify stock or estimate what will work for you.
Choose a comparison amount for the arithmetic, not as a daily target. Results can represent part of a label serving; they do not mean a tablet can be divided accurately or that you should take that amount. IU, CFU, DFE, RAE and blends without a declared ingredient amount are outside this tool’s scope.
Three Worked Price Examples
All prices and labels in the examples below are hypothetical. The comparison amounts are not dosing advice.
Magnesium: A Cheaper Bottle Can Cost More
Product A costs $30 for 60 servings with 200 mg elemental magnesium each: $0.50 per serving and $0.25 per 100 mg. Product B costs $24 for 60 servings with 100 mg each: $0.40 per serving but $0.40 per 100 mg. A costs 37.5% less per equal amount, despite its higher bottle price. This does not establish that its form is the better choice for you.
Omega-3: Count EPA + DHA
A hypothetical $24 bottle with 60 servings, each containing 180 mg EPA and 120 mg DHA, provides 300 mg EPA + DHA per serving. It costs about $1.33 per 1,000 mg EPA + DHA. Enter 300 mg, not a larger total-fish-oil number from the front of the bottle.
Creatine: Different Units, The Same Price Basis
Product A costs $30 for 60 servings of 5 g: $0.50 per 5 g. Product B costs $24 for 80 servings of 3,000 mg: also $0.50 per 5 g. B has the cheaper label serving, but they tie at the same ingredient amount. This example compares the same declared form; it does not establish equivalence between creatine monohydrate and HCl.
You can copy or print a completed calculation. Entered values are used in your browser; they are not added to the page URL or sent in tool analytics events. The copied result identifies your entries, not a live retailer offer.
What To Check Before Buying
- How The Supplement Explained Score Works: see the criteria beyond price. The editorial score is not a percentage effectiveness rating.
- Prepare A Supplement Interaction Check: use it to prepare questions, not to establish that a product is safe.
- Browse Our Product Analyses: check exact labels, package sizes and tradeoffs.
Sources
- NIH Office of Dietary Supplements: magnesium, including elemental magnesium on supplement labels.
- NIH Office of Dietary Supplements: omega-3 fatty acids, including EPA, DHA and differences in supplement formulations.
- NOW Magnesium Glycinate Tablets: manufacturer label reference for the separately identified real-product example.
