How to Calculate Maintenance Calories When You're on Mounjaro or Wegovy

Your maintenance calorie level is determined by your Total Daily Energy Expenditure (TDEE) — the total energy your body burns in a day. It combines your Basal Metabolic Rate (BMR), which is the energy used just to keep you alive at rest, with an activity multiplier that accounts for how much you move.

The basic formula

BMR is most commonly estimated using the Mifflin-St Jeor equation, which factors in your weight (kg), height (cm), age, and biological sex. Your estimated BMR is then multiplied by an activity factor — typically ranging from around 1.2 for very sedentary days to 1.7 or above for highly active ones — to give your TDEE. This TDEE figure is your maintenance calorie estimate.

It is worth stressing that these are estimates. Individual metabolism, muscle mass, hormonal factors, and the physiological effects of tirzepatide or semaglutide all influence actual energy expenditure, so treat any calculated number as a useful starting point rather than a fixed target. A maintenance calories calculator can run this maths for you instantly based on your current stats.

Why it matters on a GLP-1 journey

Reduced appetite is one of the most commonly reported effects of medicines like Mounjaro and Wegovy. Many people find they are eating significantly less than before — sometimes less than their body needs to preserve muscle and support energy levels. Understanding your maintenance figure helps you gauge whether your intake is in a sensible range, and gives you and your prescriber a useful reference point.

If you want to go further and model a calorie deficit, the page on working out a weight-loss calorie target covers how to approach that. For a broader overview of calorie maths, the guide on how to calculate your daily calories is a good companion read.

How your maintenance number changes over time

As you lose weight, your BMR decreases — a lighter body needs fewer calories at rest. This means your maintenance figure is not static; it shifts downward as your weight does. Recalculating every few weeks, or whenever your weight changes noticeably, keeps the estimate accurate and helps you spot why progress may have slowed.

Manually recalculating maintenance calories and then logging every meal is a lot to juggle — particularly when appetite fluctuates week to week. GLP Trackr's food logging makes this significantly easier.

The quickest way to log a meal is the AI photo scan: point your camera at your plate and the app produces an instant calorie and macronutrient breakdown, no manual searching needed. For packaged foods, the barcode scanner pulls in nutrition data in seconds. You can also set a personal calorie target inside the app so you can see at a glance how your day's intake compares to your goal — and whether you are hitting a reasonable range relative to your maintenance estimate.

Because your maintenance figure changes as your weight changes, the daily weight check-in in GLP Trackr gives you a running record of exactly that shift. Combine logged food intake with your weight trend and you start to see a genuinely useful picture: not just what you ate, but how your intake relates to your progress over time. The full calorie calculator hub pulls together all the tools that support this kind of joined-up tracking.

General educational ranges for calorie intake are a useful guide, but the right target for you personally depends on your individual circumstances and health history. Always discuss specific nutrition goals with your prescriber or a registered dietitian — GLP Trackr helps you record and observe your intake, and is not a substitute for professional advice.

Ready to take the guesswork out of calorie tracking? Download GLP Trackr on the App Store or Google Play and start your free 7-day trial — log meals, set targets, and watch how your numbers move as your journey progresses.