Health & Fitness
Calculate fitness metrics, track your health, and build habits that stick, all privately in your browser.
Measure & Plan
Keep It Up
About Health & Fitness
Body measurements, energy needs, nutrition targets and a few habit trackers. The calculators use the standard published formulas, which are named on each tool rather than hidden, because the formula is the assumption.
That naming matters more here than anywhere else on the site. BMI was designed to describe populations and not individuals, and it cannot tell muscle from fat. Calorie needs come from equations fitted to averages, so a result is a starting estimate to adjust from, not a measurement of you. Each tool says where its number is weakest rather than presenting an estimate as a fact.
The trackers keep their history in your browser only. Nothing here is uploaded, which for this category is the whole point.
Guides
How the health & fitness calculations work, and where they go wrong.
- How Much Protein You Actually Need
- How Running Pace and Race Predictions Work
- How to Build a Daily Movement Habit With a Streak
- How to Calculate BMI (and What It Really Tells You)
- How to Calculate TDEE and Your Daily Calories
- How to Calculate Your Macros From Calories
- How to Estimate Your One Rep Max
- How to Find and Train in Your Heart Rate Zones
- How to Find Your Ideal Weight for Your Height
- How to Measure Body Fat With a Tape Measure
- How to Set a Calorie Deficit That Holds
- How to Track Body Weight Without Losing Your Mind
- How to Track Your Water Intake and Stick to It
- What Your BMR Actually Measures