Price Per MG Calculator
Two bottles, two prices, two different milligram counts: which is actually cheaper? The price per milligram cuts through packaging tricks and serving-size games. Enter what you paid and how many milligrams you got, and this calculator shows exactly what each milligram costs, to four decimal places.
Example: 60 capsules at 250 mg each fills 15,000 mg. Grams are multiplied by 1,000.
Use this number to compare products: the lower the price per mg, the better the value for the same ingredient.
Price math answers a cost question only. It says nothing about quality, purity or whether a product suits you. Estimate only, not financial or medical advice.
Quick Answer
A $45 bottle holding 15,000 mg costs $0.0030 per mg: 45 ÷ 15,000, which is $3.00 per gram and $0.30 per 100 mg. Against a $30 bottle with 8,000 mg ($0.0037/mg), your bottle wins by 20.0% cheaper per mg. If you only know capsules, the helper turns 60 capsules at 250 mg each into 15,000 mg for you.
Key takeaways
- Price per mg is total price divided by total milligrams in the whole package, shown to four decimals because the values are tiny.
- Count capsules, not servings: 60 capsules at 250 mg each is 15,000 mg of content, whatever the front of the bottle emphasizes.
- The head-to-head comparison names a winner and the exact percent saved per mg, but only within the same ingredient and grade.
- Price math answers a cost question only. It says nothing about purity, testing or whether a product suits you.
- Quick Answer
- How to use the price per mg calculator
- The formula: total price divided by total milligrams
- Worked example: two bottles, checked line by line
- The serving-size trap
- When price per mg matters most
- What competing calculators miss
- Frequently asked questions
- Add This Calculator to Your Website
- References
How to use the price per mg calculator
Enter what you paid and how many milligrams you got, then click Calculate price per mg. If you only know capsules or grams, run the helper first and it fills the milligrams for you.
- Enter the total price: what you paid for the whole package, in your own currency. $45 is pre-filled.
- Enter the total milligrams: the milligrams in the entire package, not per serving and not per capsule. The worked example uses 15,000.
- Or use the unit helper: type the quantity, pick milligrams, grams or capsules, add the mg per capsule if needed, and click Fill mg. Grams are multiplied by 1,000; capsules by their mg each; the result is rounded to two decimals.
- Optionally add Product B: its price and its total milligrams. The calculator declares a winner with the percentage saved per mg.
- Read four lines: price per mg to four decimals, price per gram, price per 100 mg (the unit supplement labels use most), and the comparison verdict.
The results stay hidden until you calculate, and Reset restores the worked example. Empty, zero or negative entries stop with a message naming the faulty field.
The formula: total price divided by total milligrams
Price per mg = total price ÷ total milligrams. Two derived lines come free: price per gram = price per mg × 1,000, and price per 100 mg = price per mg × 100.
1 gram = 1,000 milligrams, exactly (milli- = 10⁻³ in the SI system)
The milligram is one thousandth of a gram under the International System of Units described in the SI Brochure. For liquids sold by volume rather than weight, the price per 100 ml calculator covers that angle, and for bulk powders weighed in grams the price per 100 g calculator keeps the numbers readable.
Worked example: two bottles, checked line by line
The calculator is pre-filled with the full comparison. Running it produces every figure below, including the rounding the tool actually applies.
| Your bottle | Product B | |
|---|---|---|
| Price / content | $45 / 15,000 mg | $30 / 8,000 mg |
| Price per mg | $0.0030 | $0.0037 |
| Price per gram | $3.00 | $3.75 |
| Price per 100 mg | $0.30 | $0.38 |
| Verdict | Your product wins: 20.0% cheaper per mg | |
Two honest details about the arithmetic. Product B's 30 ÷ 8,000 is 0.00375, which the tool displays as $0.0037 (four-decimal rounding of the binary value), and the 20.0% saving is computed from the unrounded figures: (1 − 0.003 ÷ 0.00375) × 100. The $45 bottle is the better value even though its sticker price is higher, which is exactly the trap the next section is about.
Price per mg, bottle against bottle
The serving-size trap
The number on the front of the package is not the number you need. A bottle of 60 capsules at 250 mg each is not "60 servings of value", it is 15,000 mg of active ingredient. Price per serving rewards big capsules; price per milligram measures the actual content you are paying for.
Before you compare, multiply capsules by milligrams per capsule, or read the Supplement Facts panel for the total content. US supplement labels must declare the quantitative amount of each dietary ingredient, and serving sizes follow standardized reference amounts, both set out in federal labeling rules. The cost per dose calculator covers the per-serving angle if that is the number you need, and for piece-counted goods the cost per item calculator does the same job per piece.
When price per mg matters most
Supplements such as creatine, vitamins and protein powders are the classic case: bulk bags almost always beat small tubs per mg, and the gap is bigger than the sticker suggests. Medications and lab chemicals are the serious case: compare $/mg across vendors, but weigh it against third-party testing and reputation, because the cheapest $/mg from an untested source is not a bargain. Purity grades change what a milligram means, so only compare within the same grade.
One boundary the tool will not cross for you: different ingredients are not interchangeable just because both are measured in milligrams. A dollar per milligram of one compound says nothing about a dollar per milligram of another. The comparison is valid for the same ingredient, same grade, different package. Anything else is a category error with numbers on it.
What competing calculators miss
Price-per-mg tools split into three camps, and each leaves something on the table:
- Formula tools (Brave Calculator's price-per-mg page): the right formula and a good worked example ($45 ÷ 15,000 mg = $0.003), but no comparison mode and no unit conversion. You must arrive with total milligrams already computed.
- Article-first tools (Savvy Calculator): solid label-reading guidance with an example table, but the tool is secondary and there is no capsule-to-mg helper and no head-to-head verdict.
- CBD strength calculators: they compute mg per ml and strength percentage, which this page does not attempt, but neither of them compares two products' value per milligram.
- The gap this page fills: the only page that takes you from "60 capsules" to a head-to-head winner in one place: capsule and gram conversion built in, four-decimal precision, price per 100 mg for label mapping, and a comparison that names the winner with the exact percent saved.
Frequently asked questions
Divide the total price by the total milligrams in the whole package. A $45 bottle holding 15,000 mg gives 45 divided by 15,000 = $0.0030 per mg. The total must be the milligrams in the entire package, not per serving and not per capsule.
Multiply the capsule count by the milligrams per capsule: 60 capsules at 250 mg each is 15,000 mg. The unit helper on this page does it for you, including the grams-to-milligrams conversion (grams times 1,000).
Because supplement and CBD labels talk in tens and hundreds of milligrams. $0.30 per 100 mg is easier to map onto a label than $0.0030 per mg, and it is the same number scaled up by 100.
Because real price-per-mg values are tiny. $0.0030 per mg rounded to two decimals displays as $0.00, which is useless for comparison. Four decimals keep products distinguishable, and the per-gram and per-100-mg lines carry the readable versions.
Price per mg, when the ingredient is the same. Price per serving rewards big capsules and serving-size games; price per milligram measures the actual active ingredient you are paying for. If the per-serving number is what you need, the cost per dose calculator on this site covers that angle.
No. Different ingredients are not interchangeable just because both are measured in milligrams, and purity grades change what a milligram means. Compare within the same ingredient and the same grade; anything else is a category error with numbers on it.
It converts your quantity into total milligrams and fills the weight field. Milligrams are used as-is, grams are multiplied by 1,000, and capsules are multiplied by the mg-per-capsule figure you enter. The result is rounded to two decimals. It refuses zero or negative quantities with a message instead of filling a wrong number.
As (1 minus cheaper divided by pricier) times 100, using the unrounded values. Your $0.0030/mg against Product B's $0.00375/mg gives (1 - 0.003 / 0.00375) x 100 = 20.0% cheaper per mg. The displayed four-decimal figures are rounded, so recomputing from them by hand can differ in the last digit.
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References
- U.S. Food and Drug Administration. Dietary Supplements. Accessed October 23, 2026.
- National Institutes of Health, Office of Dietary Supplements. Dietary Supplements: What You Need to Know. Accessed October 23, 2026.
- Electronic Code of Federal Regulations. 21 CFR 101.36 - Nutrition labeling of dietary supplements. Accessed October 23, 2026.
- Electronic Code of Federal Regulations. 21 CFR 101.12 - Reference amounts customarily consumed per eating occasion. Accessed October 23, 2026.
- Bureau International des Poids et Mesures (BIPM). The International System of Units (SI Brochure). Accessed October 23, 2026.