You
Body
Activity
Goal
Plan

Let's get the basics

The estimate uses standard equations that come in two versions. Pick the one that fits you best, it only changes the math.

Your height and weight

Morning weight is the most consistent, but any honest number works.

How active is a normal week?

Count everything, job, chores, workouts. Most people overestimate; when torn, pick the lower one.

Pick a direction

Slower paces are easier to live with and protect more muscle. You can rerun this anytime.

How the planner works

Behind the friendly steps is straightforward, published science. The planner estimates your basal metabolic rate with the Mifflin-St Jeor equation, in validation studies, the most accurate of the common formulas for most adults, then multiplies it by an activity factor to estimate your total daily burn. Your calorie target is that number plus or minus a modest amount based on the direction you chose, never below a safety floor. The protein range follows the research consensus of roughly 0.7–0.9 grams per pound of body weight for people managing their weight.

What it can't do: see your muscle mass, your medical history, your medications, or your genetics. That's why the honest range on any estimate is about ±10%, and why the planner tells you to trust two or three weeks of real-world results over any formula, including ours.

Common questions

Is the Healthy Weight Planner accurate?

It uses the Mifflin-St Jeor equation, which research finds to be the most reliable of the common estimation formulas. Even so, any equation can be off by around 10% for a given individual, treat the result as a starting point and adjust based on two to three weeks of real-world results.

Why won't the planner give me a very low calorie target?

Eating below roughly 1,200 calories a day (1,500 for most men) is territory that deserves professional supervision. The planner applies those floors on purpose. If you feel you need a faster pace, that's a conversation for a doctor or registered dietitian.

Does the planner store my information?

No. Everything is calculated in your browser and nothing you enter is sent to us or saved anywhere.

Is BMI a perfect measure?

No measure is. BMI says nothing about muscle, and very muscular people can score 'high' while lean. It remains a useful population-level screening range, which is how the planner presents it, as context, not a diagnosis.

A note on health content: The planner provides general educational estimates, not medical advice, and is designed for adults 18+. If you have a medical condition, take medications that affect weight, are pregnant, or have a history of disordered eating, please work with a healthcare professional instead of a calculator.