Free Calculators

Free Health and Metabolism Calculators

These four calculators estimate different pieces of the same picture. BMI scales your weight to your height as a rough population screen. BMR estimates the calories your body burns at complete rest. TDEE adds movement and digestion on top of BMR to estimate your total daily burn. The calorie calculator takes that total and turns it into a maintenance figure and a daily target. Every one of them runs entirely in your browser, returns a result instantly, and never asks for your email.

  • 01

    BMI Calculator

    Scales your weight to your height and shows the standard adult categories, along with a clear account of what the number cannot tell you.

    What it uses

    Height, weight

  • 02

    BMR Calculator

    Estimates the calories your body burns at complete rest using the Mifflin-St Jeor equation, plus estimated daily burn at five activity levels.

    What it uses

    Sex, age, height, weight, activity

  • 03

    TDEE Calculator

    Estimates your total daily energy expenditure: resting burn plus movement plus the energy cost of digesting food.

    What it uses

    Sex, age, height, weight, activity

  • 04

    Calorie Calculator

    Estimates your maintenance calories and a daily target based on the gap between your current weight and your goal weight, with a rough timeline.

    What it uses

    Sex, age, height, weight, goal weight, activity

Your inputs stay in your browser. Nothing you type here is sent to us, saved to an account, stored, or emailed. Like any page on this site, we do record that the page was visited.

How These Four Fit Together

Three of the four form a single chain. BMR is the floor of your energy use, the calories your body spends at complete rest. TDEE is that BMR multiplied by an activity factor, so it estimates everything you burn across a full day, movement and digestion included. The calorie calculator takes that total and adjusts it toward a goal, which is where a daily target comes from. BMI sits outside that chain. It is a separate screening measure built from height and weight alone, and it says nothing about your energy needs.

What These Tools Do Not Do

Each of these is an estimate produced by a published equation, and it is worth being precise about what that leaves out.

  • They do not diagnose. No number here identifies a condition or rules one out.
  • They do not measure. The only real measurement of resting metabolism is indirect calorimetry, performed in a clinical setting. An equation predicts a value from your height, weight, age, and sex. It does not measure anything about you.
  • They do not account for medications, thyroid function, pregnancy, or body composition. All four change what your body actually needs, and none of them are inputs to any equation on this site.
  • They are not a treatment plan. A figure from a calculator is a starting point for a conversation with a clinician, not instructions for how to eat, train, or treat anything.

How Protocol MD Approaches This

Protocol MD is a physician-guided peptide therapy practice. Licensed physicians evaluate performance, longevity, and body composition, alongside recovery, sleep, energy, and cellular health. If you want the background first, here is what peptide therapy is and how it is used.

A calculator estimates energy needs. It cannot tell you whether any treatment is appropriate for you. Only a licensed physician can, after a full assessment.

Educational only. This tool does not diagnose, prevent, treat, or cure any condition, and it is not medical advice or a recommendation of any specific therapy.

Using this calculator does not create a physician-patient relationship with Protocol MD.