Calorie Calculator
Calorie intake calculator
Understanding your daily calorie needs is a powerful first step in your weight management journey. This calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), Total Daily Energy Expenditure (TDEE), and a recommended daily calorie target for weight loss. Your Karespot dietician will provide a personalised nutrition plan tailored to your GLP-1 therapy.
Calorie intake calculator
How many calories do you need each day?
Enter your details below to estimate your BMR, TDEE, and a recommended daily calorie target for weight loss. Results update live as you adjust the sliders.
Biological sexBasal Metabolic Rate (BMR)
Calories your body needs at complete rest
Energy for breathing, circulation and cell function — before any movement.
Total Daily Energy Expenditure (TDEE)
Total calories burned including all activity
Consuming this amount maintains your current weight.
Daily calorie target for weight loss
TDEE minus a 500 kcal deficit
A 500 kcal/day deficit is associated with ~0.5 kg/week weight loss. Supervised by your Karespot dietician.
What do these numbers mean?
What is BMR?
Your Basal Metabolic Rate is the number of calories your body needs at complete rest — just to keep you alive. It accounts for breathing, circulation, body temperature and cell function. BMR does not include any physical activity. This calculator estimates it using the Mifflin-St Jeor equation [1], widely regarded as the most accurate general-population formula.
What is TDEE?
Total Daily Energy Expenditure is the total number of calories your body burns each day, accounting for your activity level. Eating at your TDEE maintains your current weight. Eating below it creates a calorie deficit that drives fat loss. Activity multipliers are derived from MET values established in the Compendium of Physical Activities [2].
What is a calorie deficit?
A 500 kcal/day deficit below your TDEE is associated with approximately 0.5 kg of fat loss per week [3]. On GLP-1 therapy, your Karespot dietician will fine-tune this target to protect lean muscle mass and prevent nutritional deficiencies.
Frequently asked questions
This calculator uses the Mifflin-St Jeor equation [1], which is widely considered the most accurate general-population formula for estimating Basal Metabolic Rate. It accounts for weight, height, age and sex. However, it does not account for body composition — two people with the same height and weight but different muscle-to-fat ratios will have different true BMRs. Muscle burns more calories at rest than fat, so someone with more lean mass will have a higher actual BMR than the formula suggests.
Sedentary means mostly sitting, with little structured exercise. Lightly active means you move around during the day or do light exercise 1–3 times per week. Moderately active means regular exercise 3–5 times per week or a physically active job. Very active means daily intense exercise or a very physically demanding job. Activity multipliers in this calculator are derived from MET values established in the Compendium of Physical Activities [2]. When in doubt, most people should select ‘Lightly active’ — studies consistently show the general population overestimates how active they are.
A 500 kcal/day deficit is a commonly cited safe threshold for gradual fat loss, associated with approximately 0.5 kg of fat loss per week [3]. However, on GLP-1 therapy, appetite is already significantly reduced [4] — many patients naturally eat well below their TDEE without counting calories. In this context, trying to eat even less risks nutritional deficiencies, fatigue, and accelerated muscle loss. Your Karespot dietician will assess your actual intake and focus on food quality and protein adequacy first.
GLP-1 medications reduce appetite and slow gastric emptying [4], which means most patients naturally consume significantly fewer calories while on treatment. They do not fundamentally change your BMR or TDEE in the short term, but sustained weight loss does reduce BMR slightly as your body mass decreases [5]. This is why TDEE recalculation is recommended at regular intervals during treatment.
Strict calorie counting is not required or recommended for all patients on GLP-1 therapy. Because appetite is already suppressed by the medication [4], the more important focus is on food quality — specifically getting sufficient protein, micronutrients, and fibre within a reduced total intake. Your Karespot dietician will advise whether food tracking is appropriate for your specific situation.
Your Karespot dietician goes beyond the calculator
Calorie targets are a useful guide, but GLP-1 therapy changes your metabolic picture. At Karespot, we don't hand you a diet plan and expect you to follow it perfectly. Your registered dietician tracks what you actually eat, runs weekly audits, and identifies small, practical improvements you can make every day — calibrated to protect lean muscle, prevent nutritional deficiencies, and support a lasting, healthy relationship with food.
Clinical & Scientific References
- 1 Mifflin MD, St Jeor ST, Hill LA, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247. PubMed ↗ — The original validation study establishing the Mifflin-St Jeor equation as the most accurate general-population formula for estimating resting energy expenditure; the standard used in this calculator.
- 2 Ainsworth BE, Haskell WL, Herrmann SD, et al. 2011 Compendium of Physical Activities: a second update of codes and MET values. Med Sci Sports Exerc. 2011;43(8):1575–1581. PubMed ↗ — Comprehensive reference for metabolic equivalent (MET) values used to derive activity multipliers applied to BMR to calculate TDEE.
- 3 Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826–837. PubMed ↗ — Mathematical modelling study establishing the relationship between calorie deficit and body weight change; underpins the 500 kcal/day deficit ≈ 0.5 kg/week fat loss estimate.
- 4 Wilding JPH, Batterham RL, Calanna S, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021;384:989–1002. STEP 1 trial ↗ — Phase 3 RCT demonstrating significant appetite suppression on semaglutide; confirms GLP-1 does not alter BMR directly but drives calorie intake reduction and secondary changes in body mass.
- 5 Müller MJ, Enderle J, Pourhassan M, et al. Metabolic adaptation to caloric restriction and subsequent refeeding: the Minnesota Starvation Experiment revisited. Am J Clin Nutr. 2015;102(4):807–819. PubMed ↗ — Evidence that BMR decreases proportionally with sustained weight loss — supporting the need to recalculate TDEE at intervals during GLP-1 treatment.