Stop guessing your dose. Get the number that's backed by research.
Every supplement calculator here is built from the actual science — clear inputs, an honest answer, and a plain-English explanation of why. No fluff, no broscience, no upsell disguised as advice.
The calculators
Live now, plus what's coming. Each one is validated against the research before it ships.
Creatine calculator
Your loading and maintenance dose by bodyweight, days to full muscle saturation, and monthly cost.
Open calculator →Protein for GLP-1 users
How much protein to hit on Zepbound or Ozempic to hold onto muscle while losing weight.
In the worksCreatine & water intake
How much water to drink day to day while you're supplementing creatine.
In the worksBuilt from the research
Doses come from primary sources like the ISSN position stands — not from whatever's trending on gym TikTok.
We flag the limits
Where the science is fuzzy or a "hack" doesn't hold up, we say so instead of selling you certainty.
A number and a reason
You get the figure you came for, plus a plain explanation of how it's worked out — so you can trust it.