How to Estimate Your BMR and Daily Calorie Needs

BMR estimates the calories your body burns at rest over 24 hours. It is not the same as your total daily energy expenditure (TDEE), which also accounts for physical activity. To estimate your daily intake of calories realistically, most people multiply their BMR by an activity factor — a sedentary person might multiply by around 1.2, while someone moderately active most days might use 1.5 or higher. These are educational ranges; what your body actually needs can vary, and a prescriber or registered dietitian can give personalised guidance.

Common BMR Formulas

The two most widely used equations are the Mifflin-St Jeor and Harris-Benedict formulas. Both use weight, height, and age to produce an estimate. Neither is perfectly precise — they produce averages based on population data — but they give a practical starting point for understanding whether you are eating broadly in the right range.

• Average BMR for women is often quoted in the range of roughly 1,400–1,600 kcal per day at rest, though this varies significantly with body composition and age.
• Average BMR for men tends to be somewhat higher, often in the range of roughly 1,700–1,900 kcal per day at rest, again with considerable individual variation.
• Multiplying either figure by an activity factor gives a more realistic picture of a man's or woman's daily intake of calories.

BMR on a GLP-1 Journey

Medicines like Mounjaro and Wegovy work on appetite-regulating pathways, and many people find they are eating considerably less than they were before. Understanding your BMR helps you check that you are still meeting a reasonable baseline for protein and nutrients — particularly important when portions are smaller. For guidance on hitting specific macro targets, see our page on how to track macros on a GLP-1 journey, and for a broader look at calorie estimation tools, the calorie calculator hub covers the full picture. You can also calculate your calories directly or use our calories calculator for a quick estimate.

A note on terminology: kcals and calories refer to the same unit as used on food labels — one kilocalorie (kcal) equals one dietary calorie. The terms are interchangeable in everyday nutrition contexts.

Manually cross-referencing a BMR estimate against everything you eat is time-consuming — and on a GLP-1 medicine, when meals are smaller and less predictable, it is easy to lose track of whether you are hitting your protein and calorie targets. GLP Trackr's food logging feature is built to make this effortless: point your camera at a meal and the AI photo scan returns an instant nutrition breakdown, including calories, protein, and macros. There is also a barcode scanner and manual search for packaged foods.

Once you have estimated your BMR and worked out a rough daily calorie target with your prescriber or doctor, you can set that figure as a target inside the app. GLP Trackr then tracks your intake against it in real time, so you can see at a glance whether you are on track — useful on days when appetite is very low and under-eating is a real risk. The app's insights feature can also surface patterns, such as how your protein intake relates to your energy levels or weekly progress.

Any specific calorie or macro target that matters clinically — for example if you have diabetes or another condition — should be agreed with your healthcare professional, not set solely from a BMR calculator. GLP Trackr helps you record and hit the targets you and your prescriber decide on together; it is not a substitute for that conversation.

Ready to put your BMR estimate to work? Download GLP Trackr on the App Store or Google Play and start a free 7-day trial — set your calorie target, log your meals with a snap, and see your nutrition picture come together every day.