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Calorie deficit calculator: Find your daily target
Calculate your calories
Enter your details below to estimate your maintenance calorie.
Important – This tool is intended for general healthy weight management guidance only. If you have a history of disordered eating, are currently underweight, or are being treated for an eating disorder, pregnant, breastfeeding, trying to gain weight after illness, do not use this calculator without first speaking to your GP or a registered dietitian. For eating disorder support, contact the Butterfly National Helpline or healthdirect.
Enter your age (19-80 years). As we age, our metabolism naturally slows, which can affect our daily calorie requirements.
Enter your height in centimetres. Height can help us to estimate your body's daily energy requirements.
Enter your current weight in kg. Weight is used to measure how much energy your body needs each day.
*Estimates only. See full clinical & legal disclaimer below.
Understanding maintenance calories vs. a calorie deficit
With so many diets promising speedy results, from keto and intermittent fasting to detoxes and low-carbohydrate eating, it’s easy to become overwhelmed. While varied eating habits may fit different people, good weight control ultimately boils down to one simple principle: energy balance.
Your body needs a certain amount of energy every day just to operate. This involves keeping your heart pumping, breathing, controlling body temperature, digesting food, and supplying energy for physical activities. A maintenance calories calculator calculates your entire daily energy demand, commonly known as total daily energy expenditure (TDEE).
If you consume nearly the same number of calories as your TDEE, your weight will likely remain pretty steady over time.
However, it’s important to recognize that weight management is not a simple “calories in, calories out” equation for everyone. Factors such as hormone imbalances, menopause, mental health, disabilities, eating disorders, and medications play a massive role in how our bodies process and store energy.
A calorie deficit calculator estimates how many calories you should consume if you want to lose weight. By consuming fewer calories than your body requires, your body begins to use stored fat as an energy source.
The size of your caloric deficit is important. A moderate deficit is often simpler to sustain, encourages healthy eating habits, and lowers the risk of muscle loss. Large deficits may cause weariness, hunger, and trouble adhering to your strategy.
Remember that this weight loss calculator only gives an estimate. Individual calorie requirements vary depending on muscle mass, genetics, hormones, medicines, and underlying health issues.
How does this calorie calculator work?
Our calorie calculator employs the scientifically validated Mifflin-St Jeor equation, which is one of the most often used techniques for predicting daily energy requirements in healthy humans. Healthcare professionals and nutritionists widely use this method because it gives a realistic estimate of calorie requirements based on publicly available data.
The calculation is performed in two easy stages.
Step 1: Estimate your basal metabolic rate (BMR)
Your Basal Metabolic Rate (BMR) is the amount of energy your body requires to perform basic processes at rest. Even if you spent the whole day in bed, your body would still burn calories to keep your organs working, blood flowing, hormones balanced, and body temperature stable.
Your BMR is computed using the following:
- Age
- Biological sex
- Height
- Weight
Step 2: Calculate your total daily energy expenditure (TDEE)
Next, the calculator multiplies your BMR by an activity factor based on your lifestyle choice.
Someone with a desk job who rarely exercises would burn fewer calories than someone who exercises often or works in a physically demanding environment. This gives you your anticipated maintenance calories, which are the total number of calories your body uses in a normal day.
Following that, the calculator predicts calorie targets for progressive, sustainable weight loss with a modest calorie deficit. Although no calorie calculator can be completely precise for everyone, the Mifflin-St Jeor equation is widely regarded as one of the finest evidence-based methods for determining daily calorie requirements.
Remember that calorie estimations should only be used as a starting point, not as a precise prescription. Your body’s energy requirements might fluctuate with age, weight changes, muscle gain, pregnancy, illness, medications, and exercise levels.
The dangers of extreme calorie deficits
When you want to lose weight, it’s tempting to drastically reduce your calorie intake. Diets that promise quick results by limiting you to 800-1,200 calories per day may appear appealing, but most people find them difficult to follow and can pose health risks. Therefore, very low-calorie or very low-energy diets should only be followed with medical supervision.
A calorie deficit is required for weight reduction, but more is not necessarily better. When you continuously eat fewer calories than your body requires, it begins to conserve energy. This might leave you feeling fatigued, irritable, and always hungry, making it difficult to maintain healthy eating habits.
A severe calorie shortage can also:
- Increase muscle loss along with fat loss.
- Slow down your metabolic rate over time.
- Make it difficult to obtain adequate vitamins and minerals.
- Reduces workout performance and recovery time.
- Affect mood, attention, and sleep.
- Increase the risk of binge eating or weight regain after the diet ends.
For the majority of people, Australian health specialists recommend aiming for steady, sustained weight loss of 0.5-1 kg each week. This typically entails creating a daily calorie deficit of about 500 calories; individual requirements vary.
Instead of pursuing immediate cures, focus on developing long-term behaviours. A moderate calorie deficit combined with regular physical activity, enough protein consumption, and good-quality sleep is often more beneficial than restrictive diets.
If you have a medical condition such as PCOS, thyroid illness, diabetes, or are pregnant or nursing, consult your doctor or an accredited practising dietitian before making substantial dietary changes.
4 tips for sticking to your calorie deficit
- 1
Use a calorie counter
Most individuals accidentally underestimate how much they consume. Portions can add up quickly, especially when dining out or nibbling throughout the day.
Using a calorie counter app for a few weeks will help you better understand serving sizes and identify hidden calories. Popular applications such as MyFitnessPal, Cronometer, and Easy Diet Diary enable you to record meals, scan barcodes, and track your daily consumption. You don’t have to monitor forever, but it may be a useful learning tool for developing healthy behaviours.
- 2
Make protein a priority at each meal.Protein keeps you fuller for longer and promotes muscle maintenance throughout weight reduction. It also has a greater thermic impact than carbs or fats, meaning your body expends slightly more energy to break it down. Aim to incorporate a quality protein source in most meals, such as:
- Chicken or turkey
- Fish and seafood
- Eggs
- Greek yogurt
- Tofu and tempeh
- Legumes and beans
- Lean meat or lamb
- 3
Consume high-volume, nutrient-dense meals.Weight loss doesn’t mean eating small meals. Choosing foods that are naturally low in calories but high in fibre and water helps you to consume filling meals while keeping within your calorie budget. Excellent choices include:
- Leafy greens
- Broccoli, cauliflower, and tomatoes
- Carrots and cucumbers
- Berries and apples
- Air-popped popcorn
- 4
Avoid drinking caloriesCalories from liquids are easy to ignore because they do not provide the same sense of fullness as solid foods. Hidden calories are commonly found in the following foods:
- Soft beverages
- Fruit Juice
- Flavoured milk
- Large café coffees with flavoured syrups
- Alcohol
- Sugared energy drinks
Calorie tracking & weight loss FAQs
1. How many calories should I consume to lose 1 kilogram every week?
To shed around 1 kg of body fat each week, you typically require a weekly calorie deficit of around 7,700 calories, which equates to about 1,000 fewer calories per day. While this may be acceptable for certain people under medical care, it is frequently too aggressive for many adults. A smaller calorie deficit is typically easier to sustain and reduces the risk of fatigue, muscle loss, and nutritional deficiencies. Gradual weight loss is more sustainable and simpler to maintain over time.
2. What is a calorie deficit calculator?
A calorie deficit calculator calculates how many calories your body burns each day and estimates a daily calorie target for healthy weight reduction. It calculates your Total Daily Energy Expenditure (TDEE) based on your age, height, weight, biological sex, and exercise level. The calculator then subtracts the required number of calories to generate a long-term calorie deficit while maintaining muscle mass and overall health.
Note: Muscle maintenance and overall health also depend on protein intake, resistance exercise, sleep, medical history and whether the target is appropriate for you.
3. Are all calories equivalent to weight loss?
In terms of weight reduction, calories are just a unit of energy. Consuming fewer calories than your body burns often results in weight loss, regardless of where those calories come from. However, the quality of your calories is still important. Foods high in protein, fibre, healthy fats, vitamins, and minerals help you feel satiated for longer and promote overall health. In contrast, highly processed foods and sugary beverages are often less satisfying and may make it more challenging to maintain a calorie deficit.
4. Why am I not losing weight, being in a caloric deficit?
If you are not losing weight while eating in a calorie deficit, there may be several reasons. The most prevalent is underestimating calorie intake or overestimating calorie expenditure during exercise. Other reasons include fluid retention, hormonal fluctuations, inconsistent monitoring, reduced physical activity, and metabolic adaptation during extended dieting. Several medical problems, including hypothyroidism and PCOS, can influence weight control. If you’ve consistently followed your calorie target for several weeks without progress, it’s worth discussing your concerns with a GP or accredited practising dietitian.
5. Is it safe to eat 1,200 calories a day?
For most individuals, 1,200 calories per day is insufficient to meet their nutritional and energy needs. While very low-calorie diets may be indicated for some medical conditions, they should only be followed under the guidance of a healthcare professional. Consistently eating too little can cause weariness, nutritional deficits, muscle loss, impaired focus, and a decreased metabolic rate. Instead of focusing on the lowest possible calorie intake, strive for a moderate calorie deficit that supports consistent, long-term weight loss while providing the nutrients your body needs to function properly.
6. Can a GP help me lose weight?
Yes. A GP can assess your overall health, investigate contributing factors, and discuss appropriate next steps with you.
Depending on your circumstances, your general practitioner may:
- Determine your overall health and weight objectives.
- Request blood testing to screen for illnesses, including hypothyroidism and diabetes.
- Refer you to an accredited practising dietician nutritionist or fitness professional.
- Provide continual support and track your success.
If you’ve been trying to lose weight despite healthy eating and regular exercise, schedule a consultation to investigate any underlying issues.
7. Should I eat back the calories I burn exercising?
Usually, no. If you’ve already chosen the appropriate activity level in this calorie calculator, your predicted maintenance calories should already include your typical exercise. Many smartwatches, fitness trackers, and gym machines overestimate how many calories you burn when exercising. Eating all of these predicted calories could reduce or eliminate your calorie deficit.
If you’ve had an extraordinarily lengthy or strenuous training session, you could want extra nourishment, especially if you’re preparing for endurance sports. Otherwise, most people find more consistent outcomes by sticking to their calorie goals and tracking their progress over time.
8. What are maintenance calories?
Maintenance calories are the number of calories your body needs every day to maintain its present weight. This estimate covers the energy your body expends on essential operations like breathing, digestion, and circulation, as well as everyday physical activity. If you consume your maintenance calories regularly, your weight should stay reasonably steady over time. Eating more than this amount may result in weight gain, whereas eating less creates a calorie deficit, which can aid weight reduction. Although maintenance calories are a good starting point, they are only estimates. Monitoring your weight and modifying your calorie intake accordingly can help you remain on track.
Healthy weight loss is about consistency, not perfection.
Successful weight control does not include adopting the latest trendy diet or eliminating whole food categories. It is about developing long-term habits that you can stick to for months or years rather than just a few weeks. This calorie calculator gives a useful starting point for estimating your maintenance calories and setting reasonable daily calorie goals.
Combining these estimations with regular physical exercise, proper nutrition, enough sleep, and patience can help you achieve long-term improvements. Remember that development is not always linear. Hydration, hormones, exercise, or changes in habit can all cause normal weight fluctuations. Rather than focusing on daily changes, look for patterns over a few weeks and appreciate gains in energy, fitness, and general health.
Disclaimer
This calculator only gives estimations. It uses the scientifically established Mifflin-St Jeor equation to calculate your daily calorie requirements based on your age, biological sex, height, weight, and level of physical activity. Individual changes in metabolism, muscle mass, genetics, drugs, pregnancy, menopause, or medical disorders such as hypothyroidism, polycystic ovarian syndrome (PCOS), or diabetes are not accounted for by the findings.
This tool is meant for general educational purposes and does not substitute personalised medical advice. Consult your general practitioner, an accredited practising dietitian, or another trained healthcare professional before making substantial changes to your diet, exercise regimen, or weight management strategy. If you have unexplained weight fluctuations, persistent trouble losing weight, or symptoms that concern you, get medical attention for a thorough evaluation.
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