Free Calorie & Macro Calculator
Estimate your daily calories, protein, carbohydrates and fat using your age, size, activity level and goal. Get a clear educational starting point for weight maintenance, gradual weight loss or muscle gain.
Calculate your daily calorie and macro targets
For adults aged 18 and over. Your result is an estimate, not a prescription, and should be adjusted around your health, progress and professional advice.
Your estimated daily targets
Complete the form to see estimated calories, protein, carbohydrates, fat, BMR and TDEE.
Your daily starting targets
- Estimated BMR—
- Estimated TDEE—
- Goal adjustment—
- Selected activity—
What your calorie and macro results mean
Your results combine an estimated energy requirement with a simple macronutrient split. Each number has a different purpose.
Calories
Your daily calorie figure is an estimated energy target for your selected goal. Real needs can vary, so observe your energy, hunger and progress over time.
Protein
Protein contributes to the maintenance and growth of muscle. The calculator uses your body weight and goal, with a sensible percentage cap.
Carbohydrates
Carbohydrates provide energy for daily life and exercise. The calculator assigns the calories remaining after estimated protein and fat targets.
Fat
Dietary fat supports normal body functions and helps provide energy. This tool estimates fat at approximately 30% of the daily calorie target.
BMR and TDEE are not the same
BMR, or basal metabolic rate, estimates the energy your body uses at rest. TDEE, or total daily energy expenditure, applies an activity multiplier to estimate the energy used across a typical day. Your goal target begins with TDEE rather than BMR.
How the calorie and macro calculator works
The tool uses the Mifflin–St Jeor equation to estimate resting energy expenditure, then applies your selected activity level and a modest goal adjustment.
Estimate resting energy
Age, weight, height and the equation’s sex-specific constant are used to estimate basal metabolic rate.
Estimate daily expenditure
BMR is multiplied by your chosen activity factor to produce an estimated total daily energy expenditure.
Apply your goal
The tool uses maintenance TDEE, a 10% reduction for gradual weight loss or a 5% increase for gradual muscle gain.
Mifflin–St Jeor equations used
Male: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
Female: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
The original research describes resting energy expenditure, while activity multipliers are used here to create a practical daily estimate. Predictive equations cannot measure your individual metabolism with complete accuracy.
Which activity level should you select?
Choose the description that reflects your normal week, including both planned exercise and everyday movement. If you are between two levels, starting with the lower one may produce a more conservative estimate.
| Activity level | A practical description | Multiplier |
|---|---|---|
| Sedentary | Mainly seated work, little planned exercise and limited daily walking. | 1.2 |
| Lightly active | Light exercise or purposeful movement approximately one to three days each week. | 1.375 |
| Moderately active | Moderate exercise approximately three to five days each week. | 1.55 |
| Very active | Hard exercise most days, often alongside an active daily routine. | 1.725 |
| Extra active | Intense training, multiple sessions or a demanding physical occupation. | 1.9 |
Calorie and macro targets for different goals
A calculator gives you a starting point. Your routine, food quality, sleep, training, health and consistency still matter.
Weight maintenance
Use estimated TDEE as your initial calorie reference. Track broad trends over several weeks rather than reacting to normal day-to-day changes.
- Build balanced, enjoyable meals
- Keep activity reasonably consistent
- Adjust gradually when needed
Gradual weight loss
The calculator applies a modest 10% reduction to estimated TDEE. This is an educational starting point, not an instruction to eat below your needs.
- Prioritise filling, balanced meals
- Review energy, hunger and wellbeing
- Seek qualified advice when unsure
Muscle gain
The calculator adds 5% to estimated TDEE and provides a higher protein starting point. Progressive strength training and recovery are also important.
- Follow a progressive programme
- Eat a varied, balanced diet
- Allow time for sleep and recovery
How to use your macro estimate in real life
You do not need to make every meal mathematically perfect. Use the estimate to create a simple routine that supports variety, enjoyment and consistency.
Start with a weekly plan
Choose a manageable set of breakfasts, lunches, dinners and snacks that fit your schedule.
Spread protein out
Include a useful protein source across meals rather than trying to fit the entire target into one sitting.
Choose varied foods
Include vegetables, fruit, fibre-rich carbohydrates, protein foods and appropriate sources of dietary fat.
Review the trend
After a few weeks, consider energy, hunger, training and general progress before making a small adjustment.
Calorie and macro calculator FAQs
Quick answers about calories, macros, BMR, TDEE and using your result responsibly.
How many calories should I eat each day?
Daily calorie needs vary with age, sex, height, weight, activity, health and goals. The NHS gives broad population guides of around 2,000 calories for an average woman and 2,500 for an average man, but individual needs can differ. This calculator provides an estimate based on your own entries.
What are macros?
Macros, or macronutrients, are nutrients the body needs in relatively large amounts. The three calculated here are protein, carbohydrates and fat. Protein and carbohydrates provide approximately four calories per gram, while fat provides approximately nine calories per gram.
What is the difference between BMR and TDEE?
BMR estimates how much energy your body uses at rest for essential functions. TDEE estimates your total daily expenditure after an activity multiplier is applied. TDEE is therefore normally higher than BMR and is the starting point used for the goal calculation.
How accurate is a calorie and macro calculator?
A calculator is an estimate based on population equations and self-reported activity. Metabolism, body composition, health, medication and actual movement vary between people. Use the result as a starting point, monitor broader trends and seek professional advice for individual nutrition needs.
Why does the calculator ask for sex?
The Mifflin–St Jeor equation uses different constants for male and female physiology. The field is included only because the equation requires one of those inputs. The result remains an estimate and may be less suitable when those constants do not reflect your circumstances.
How much protein do I need?
Protein needs vary according to body size, diet, activity, age and health. This tool uses a body-weight estimate and caps the result so protein does not take an excessive share of calculated calories. A registered dietitian can provide guidance for medical, athletic or specialist needs.
How often should I recalculate my macros?
Recalculate after a meaningful change in body weight, usual activity or goal rather than reacting to daily fluctuations. For most people, reviewing the estimate after several weeks is more useful than changing targets frequently.
Can someone under 18 use this calculator?
No. This tool is designed for adults aged 18 and over. Children and teenagers have different energy requirements because they are still growing. A parent or carer should seek guidance from a GP, registered dietitian or an appropriate child-health service.
Can I use this calculator during pregnancy or breastfeeding?
This calculator is not designed for pregnancy or breastfeeding because energy and nutritional needs change during these stages. Ask a midwife, GP or registered dietitian for advice that reflects your health and circumstances.
Does the calculator store my information?
No. The calculation runs in your browser and this tool does not save or transmit the age, sex, height, weight, activity or goal you enter. Printing your result uses your browser’s standard print function.
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Lifestyle Hub Today creates accessible lifestyle guides and tools designed to help readers make informed, realistic choices. This calculator explains its method, limitations and sources so you can understand how the estimate was produced.
Published: 13 February 2026
Updated: 22 July 2026
Editorial review: Lifestyle Hub Today
Evidence used for this page
The calculation and supporting explanations draw on the original Mifflin–St Jeor research and general NHS healthy-eating guidance.
Health and nutrition disclaimer
This calculator provides general estimates for educational purposes only. It is not medical advice, a diagnosis or a personalised diet plan. It is not suitable for anyone under 18, during pregnancy or breastfeeding, or for people with an eating disorder, a history of disordered eating, a medical condition or specialist nutritional needs. Speak with a GP or registered dietitian before changing your diet if you have concerns about your health or results.
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