About Cal Core

Cal Core is a simple calorie-to-activity converter. Tell it how many calories you ate, and it shows you roughly how long different activities — walking, running, cycling, swimming, and more — would take to burn that off.

Why we built it

Calorie counts on food labels and apps can feel abstract. Turning a number like "650 kcal" into "about 55 minutes of cycling" makes it easier to picture, and a little more useful for everyday decisions.

How the numbers work

Estimates are based on the MET (Metabolic Equivalent of Task) system, a standard way of expressing how much energy an activity uses relative to resting. Combined with your weight and fitness level, this gives a reasonable estimate of calories burned per minute for each activity. You can see the exact formula and numbers behind your result on the results screen.

The MET values themselves come from the Compendium of Physical Activities, the same peer-reviewed reference dataset used by researchers and public-health bodies. We document the full formula, the citation, the fitness-level adjustments, and the known limits of the estimate on our Methodology & Sources page.

Who it's for

Cal Core is for anyone who wants a quick, concrete sense of what a meal "costs" in movement — the curious, the casually health-conscious, and people who just find the trade-off interesting. It is deliberately not a medical or clinical tool, and it is not designed for managing an eating disorder or a diagnosed medical condition. For those, please speak with a qualified professional.

How we write our content

Our activity descriptions and guides are written to be accurate and genuinely useful, grounded in established exercise-physiology principles and the Compendium's MET data. Where a figure is a rule of thumb or an approximation, we say so plainly rather than dressing an estimate up as a precise fact. We'd rather be honest about uncertainty than overstate what a calculator can know about your individual body.

These are estimates, not precise measurements — see our Disclaimer for details.

What's next

We're working on a companion app with AI food scanning, personalized tracking, daily goals, and guided workouts. You can join the waitlist from the home page to hear when it launches.

Contact

Questions, feedback, or ideas? Email us at cad.bendy.bu@gmail.com.