Type the price, the servings and the amount per serving from each label, and how much of the ingredient you want a day. You get what each bottle really costs a day, a month and a year, and per gram of the ingredient — not per bottle.
Cheapest at 600 mg a day
$0.42 a day At 600 mg a day, Bottle B is the cheapest: $0.42 a day. Bottle A costs 1.2× as much for the same amount.
Valentino’s Naturals prices every review this way: “Cost per effective daily serving, not cost per bottle. A cheap bottle you take three of is not cheap.”
This is arithmetic on your own labels, not medical advice — and a cheaper dose is only a saving if it is a dose you should take. Check an amount with your doctor or pharmacist first, especially if you take blood thinners, antidepressants or blood-pressure medication.
A supplement’s real cost is what one day of the amount you want costs, not the price of the bottle. Divide the price by the servings to get the cost per serving, then multiply by the servings it takes to reach your daily amount. At 600 mg a day, a $14.99 bottle of 60 servings of 300 mg costs more than a $24.99 bottle of 60 servings of 600 mg — this calculator does that arithmetic for up to four labels at once.
How to use it
From each label, type the price, the servings per container and the amount of the ingredient you are comparing in one serving — the line on the Supplement Facts panel, not the weight of the capsule. Then type how much of that ingredient you want a day. The answer is the cheapest bottle at that amount, with every bottle’s cost a day, a month and a year, per gram of the ingredient, and how many days the bottle lasts. Leave the daily amount empty and it compares one serving a day, as the labels do.
The arithmetic
- Cost per serving = price ÷ servings per container.
- Servings a day = the amount you want ÷ the amount in one serving. A label with 300 mg a serving takes two servings to make 600 mg.
- Cost a day = cost per serving × servings a day. A month is a day × 30.4 (365 ÷ 12), a year a day × 365.
- Cost per gram of the ingredient = price ÷ (servings × grams in one serving). It is the one number that does not care how the maker cut the servings.
- Days the bottle lasts = servings ÷ servings a day.
Bottles are ranked on the fairest basis every one of them can be priced on: your daily amount if every label gives its amount, per gram if you left the daily amount empty, and per serving only when a label hides its amount — and then the page says a serving is not a dose.
One bottle, four ways to take it
| Servings a day | A day | A month | A year | The bottle lasts |
|---|---|---|---|---|
| 1 | $0.42 | $12.67 | $152.02 | 60 days |
| 1.5 | $0.62 | $19.00 | $228.03 | 40 days |
| 2 | $0.83 | $25.34 | $304.04 | 30 days |
| 3 | $1.25 | $38.01 | $456.07 | 20 days |
The shelf price is the same in every row. What changes is how many servings it takes to reach the amount you are after — which is why “60 servings” on the front of the bottle can mean a month or three weeks.
Worked examples
- The page’s example. Bottle A: $14.99 for 60 servings of 300 mg. Bottle B: $24.99 for 60 servings of 600 mg. At 600 mg a day, A takes two servings and costs $0.50 a day; B costs $0.42. A costs 1.2× as much for the same amount — $182.38 a year against $152.02 — and it runs out in 30 days, not 60.
- A cheap bottle you take three of. $12.99 for 90 servings of 100 mg against $19.99 for 60 servings of 300 mg, at 300 mg a day. The cheaper bottle is $0.14 a serving, but it takes three servings: $0.43 a day against $0.33, and 30 days against 60.
- Creatine by the tub. $25 for 500 g in 5 g scoops, at the position stand’s 3 g a day (switch the unit to g): $0.15 a day, $0.050 a gram, and the tub lasts 166 days. The monohydrate vs HCl calculator does the same for the creatine inside each form.
- A label that hides its amount. A proprietary blend gives a total, not the milligrams of each ingredient, so this calculator can only price it per serving — and it says so, rather than guessing a number the label does not print.
Common mistakes
- Comparing bottle prices. Two bottles of 60 are not the same size if one needs two servings a day.
- Trusting “servings per container”. A serving is whatever the maker says it is — one capsule, two, or four. The amount of the ingredient in it is what you are paying for.
- Using the capsule weight. A “500 mg capsule” of a 10:1 extract or a magnesium salt is not 500 mg of the thing you want. Type the ingredient line from the panel.
- Chasing the lowest cost per gram of an amount nobody studied. A cheap dose is only a saving if it is a dose worth taking. Check the amount against what the trials used first.
Frequently asked questions
How do you calculate cost per serving?
Divide the price by the servings per container. A $24.99 bottle with 60 servings is $0.42 a serving. To get what a day costs, multiply by the servings it takes to reach your daily amount.
How do you work out the price per gram of a supplement?
Divide the price by the grams of the ingredient in the whole container: servings × the amount in one serving. $24.99 for 60 servings of 600 mg is 36 g of the ingredient, so $0.69 a gram.
Why is the cheapest bottle not the cheapest per day?
Because it often holds less of the ingredient in each serving, so you take more servings to reach the same amount and the bottle runs out sooner. Cost per effective daily serving is the fair comparison.
Is a bigger bottle always better value?
Only per gram of the same ingredient at the same strength. A bigger bottle of a weaker capsule can still cost more a day. Type both labels in and see.
What if the label only shows a proprietary blend?
Then no one outside the company knows how much of each ingredient you are buying. The calculator prices it per serving and says so; the Nootropic Dose Checker shows what a blend of that size can and cannot hold.
Does a more expensive supplement work better?
The price tells you nothing about what is in the bottle. What does is the amount of each ingredient on the label, the form it is in, and whether an independent lab has tested it — a USP, NSF or Informed Sport seal.
How long will a bottle of supplements last?
Divide the servings in the bottle by the servings you take a day. 60 servings at two a day is 30 days — the last line of the table above works it out for every bottle.
Read next
- Is Mind Lab Pro worth the money?
- Proprietary blends: why you can’t tell what’s in the bottle
- Prevagen vs Alpha Brain
- Neuriva vs Alpha Brain
- Envy Nutrition Brain Support review
- The Nootropic Dose Checker — is the amount on the label the amount the studies used?
This is arithmetic on your own labels, not medical advice, and nothing here diagnoses or treats anything. Talk to your doctor or pharmacist before starting a supplement, especially if you take blood thinners, antidepressants or blood-pressure medication. Some links on this site are affiliate links: I buy what I review at full price, and a commission never changes a verdict.