About IndexBody
Free, evidence-based health calculators for people who want real answers — not vague estimates from calculators built in 2005.
Who IndexBody Is For
IndexBody was built for the person who has Googled “how many calories should I eat” and got ten different answers. For the gym-goer who wants to know their actual body fat, not just their BMI. For the person trying to lose weight sensibly without following extreme programmes. For the athlete who wants to check their FFMI. For anyone who wants health data that is accurate, cited, and free.
You should not need a gym membership or a nutritionist appointment to access reliable health calculation tools. Every calculator on IndexBody is free, runs instantly in your browser, requires no account, and never stores your data on our servers.
Our Mission
Build an accurate, transparent, and evidence-based free health calculator site. No upsells. No paywalls. No data selling. Just tools that work.
The health calculator space is dominated by outdated sites with poor design, missing citations, and calculators using formulas that were superseded decades ago. IndexBody exists to fix that. Every formula we use is documented on our methodology page with citations to the original peer-reviewed research.
What We Offer
- 31 free health calculators covering BMI, body fat, calories, macros, protein, TDEE, hydration, sleep, and more
- 28 educational articles covering everything from what BMI actually means to the fundamentals of muscle growth
- Save Results feature — save up to 20 calculator results locally in your browser with no account required
- Share and Copy — share or copy your results directly from any calculator
- Mobile-friendly — fully responsive with a dedicated mobile navigation bar
How We Source Our Formulas
IndexBody calculators are built on published, peer-reviewed formulas and guidance referenced by public health bodies such as the WHO, CDC, and NIH — for example, the standard BMI formula and Mifflin-St Jeor equation for estimating basal metabolic rate. We do not invent our own formulas or alter established equations. See our methodology page for the specific formula, source, and known limitations of each tool.
IndexBody is an informational resource, not a medical service, and content on this site has not been reviewed by a licensed clinician. For personal health decisions, always consult a qualified healthcare provider. See our full medical disclaimer · Privacy · Terms.
Our Values
Every formula is cited. Every claim is sourced. No anecdote, no guesswork.
No accounts. No tracking of personal health data. Results stay on your device.
No paywalls, no premium tiers. Every calculator and article is free forever.
We show our formulas, cite our sources, and document our methodology openly.