About Health Calculations
The purpose
Health Calculations started as the calculators we wanted to exist. Intuitive, fast, free, and built on math you can actually trust.
Each tool runs on the current peer-reviewed standard for its question, named on the page with the source linked. The calculator updates when the research does, the tools stay free, and there's no signup or email gate to get a result.
What you get
Current peer-reviewed standards
NASEM 2023 EER, Mifflin-St Jeor, Henry/Oxford, Cunningham, WHO classifications, FAO/WHO PAL: the current standard in each domain.
Cited sources
Every calculator page links the primary literature: PubMed, WHO, FAO, or the relevant clinical guideline.
Free to use
Every calculator and every feature, available to everyone at no cost.
Honest accuracy ranges
Accuracy ranges shown where appropriate. Notes on study validation when relevant.
Privacy-first
Calculations run in your browser. Your inputs aren't sent to or stored on our servers.
Updated with the research
Calculations get updated when the standards change. New tools added as we build them.
How we maintain accuracy
Each calculator follows the current peer-reviewed standard for its domain. The specific formula and source live in the calculator's own methodology section, along with any known limitations.
When better research emerges, the calculator gets updated. For a worked example of how deep this goes, open the TDEE calculator's methodology: the full coefficient set, the confidence band, and every source are laid out there.
Calculators provide estimates for general guidance. For decisions specific to your situation, a qualified healthcare professional is the right resource.