Supplement Dosage Calculator
Sensible dosing for common supplements, adjusted for your body weight where it matters.
Fill in the form and your result lands here.
Learn the details
Dosage ranges come from peer-reviewed research and established references such as examine.com and the NIH Office of Dietary Supplements. Consult a healthcare provider before starting any supplement regimen.
The supplement aisle sells certainty, and very little of it is earned. So here is the honest version: what I think actually holds up, why the amount on the label matters more than the brand on the tub, and how to tell a tested product from a hopeful one.
The short honest list
- Creatine monohydrate, the most studied sports supplement there is
- Caffeine, for the sessions that need output or alertness
- Protein powder, which is really just convenient food
- Vitamin D, where bloodwork shows you are low
That is close to the whole list. Everything else on the shelf runs from mildly useful in narrow cases to expensive urine. The tool still shows sensible ranges for a few of the middle-ground ones, because if you are going to take them anyway, you may as well take an amount somebody has actually studied.
Dose matters more than brand
The ingredient panel is where most products quietly fall apart. A blend can list ten impressive names and still hold a fraction of what the research used, because a label has to name what is inside, not promise a meaningful amount of it. Proprietary blends make that worse by hiding the split behind one combined total. Beta-alanine is the classic case: the studies ran on grams per day taken consistently for weeks, and plenty of pre-workouts carry a few hundred milligrams. Same ingredient, nothing like the same dose. Check amount per serving against the range here before you check anything else.
A worked example
At 180 pounds, the tool scales creatine to bodyweight at about 0.05g per pound, which lands on 9g a day, taken every day, with no loading phase. Loading was never necessary. It fills your muscles a bit faster and upsets some people's stomachs on the way. Caffeine scales the same way, roughly 3 to 6 mg per kg, so 82 kg comes out around 245 to 490 mg, and the bottom of that range is where I would start. Protein lands at 180g a day on the strength ratio, food first, powder for the gap.
Nobody pre-approves this stuff
Supplements are not checked for safety or contents before sale the way medicines are. Regulators can act once a problem surfaces, which means a label is a claim rather than a verified fact. The practical safeguard is third-party testing: NSF Certified for Sport or Informed Sport on the tub means an independent lab confirmed the contents match the label and screened for banned substances. It costs the brand money, which is exactly why it is a useful signal.
The last few percent
Nothing here fixes training you are not doing or eating you have not sorted. Supplements are the final few percent on top of a base that has to exist first. If you want the two that are worth the money, the creatine calculator and the protein calculator go deeper than this page does, and caffeine intake covers the daily total rather than the pre-workout scoop. If you take medication, are pregnant, or manage a health condition, run any new supplement past a doctor first. That one is not optional.
Sources: NIH Office of Dietary Supplements fact sheets
Prioritize the basics: protein powder (if needed), creatine, vitamin D, and omega-3s. Most other supplements have marginal or no benefit for most people.