About GreenMacros
GreenMacros is a free hub of fitness and nutrition calculators built on one principle: give people the exact number they came for, using the formula a sports scientist would actually use, and explain it honestly.
What we do
Every calculator on this site runs a published, peer-reviewed equation entirely in your browser. There is no account, no email wall, and no server that ever sees your numbers. Each page shows the live tool, the formula with its logic, what the result means in practice, an FAQ, and the primary scientific sources — in 25 languages.
Our accuracy & editorial policy
- Formulas are chosen for accuracy in peer-reviewed comparisons — Mifflin–St Jeor for BMR/TDEE, the U.S. Navy method for body fat, Boer for lean mass, Tanaka for max heart rate.
- Every formula is implemented from its primary source and cross-checked against worked examples before publishing.
- We state the limitations of each tool plainly (for example, BMI cannot distinguish muscle from fat). We would rather be useful and honest than impressive and wrong.
- Content is reviewed and updated as the evidence changes; the calculation logic is open in each page’s “How is this calculated?” section.
Authorship & review
GreenMacros content is built and maintained by the GreenMacros editorial team. We are not a substitute for a clinician: our role is to implement established equations faithfully, explain them in plain language, and cite the primary literature so you can check our work.
Each calculator is built directly from the original peer-reviewed paper that defines its formula, validated against worked examples, and re-checked when the evidence base changes. Every page links its sources on the Methodology page.
We are actively adding named authorship and a credentialed reviewer (a registered dietitian / physician) for the nutrition content. If you are an RD or MD and would like to review or contribute, contact us.
Medical disclaimer
GreenMacros provides estimates for general educational use. It is not medical, nutritional or training advice and is not a substitute for a qualified professional. Consult one before making significant dietary or exercise changes, and especially during pregnancy or with any medical condition.
Contact
Corrections and questions are welcome at the address below. We take accuracy reports seriously and fix verified issues quickly.