Free calorie calculatorMaintenance, loss and gain estimates
Daily Calorie Needs Calculator
Estimate how many calories you may need each day to maintain your weight. You can also see simple calorie targets for gradual weight loss or weight gain.
Important: This calculator gives an estimate only. Real calorie needs vary from person to person. Speak to a GP, dietitian or qualified healthcare professional before making major diet changes, especially if you have a medical condition, are pregnant, are under 18, have an eating disorder or are losing weight unexpectedly.
Maintenance calories
Estimate calories to stay around the same weight.
Goal targets
See calorie ranges for loss, maintenance and gain.
Your daily calorie needs are an estimate of how much energy your body uses in a typical day. This includes energy used to keep you alive at rest, plus energy used for movement, exercise, digestion and normal daily activities.
This calculator estimates your basal metabolic rate using the Mifflin-St Jeor equation, then applies an activity multiplier to estimate your total daily energy expenditure. This is often shortened to TDEE.
Quick summary
BMR estimates calories used at rest.
TDEE estimates total daily calories after activity is included.
Maintenance calories are the estimated calories needed to keep weight broadly stable.
Calorie deficit means eating fewer calories than maintenance.
Calorie surplus means eating more calories than maintenance.
How this calculator estimates calories
Step 1: Estimate BMR
The calculator estimates your basal metabolic rate using age, sex, height and weight. BMR is the starting point because larger bodies, taller bodies and younger bodies often use more energy at rest.
Men: BMR = 10 × weight kg + 6.25 × height cm − 5 × age + 5
Women: BMR = 10 × weight kg + 6.25 × height cm − 5 × age − 161
Step 2: Add activity level
Your BMR is multiplied by an activity factor. This estimates your total daily energy use, including work, walking, chores, training and other movement.
Activity level is one of the easiest places to overestimate. Think about your average week, not your best week. If you are between two levels, choosing the lower one may give a more realistic starting estimate.
Activity level
Factor
Description
Sedentary
1.2
Mostly sitting, little planned exercise.
Lightly active
1.375
Light exercise, walking or active daily routine 1–3 days per week.
Moderately active
1.55
Moderate exercise or active job around 3–5 days per week.
Very active
1.725
Hard exercise, sports or physically demanding work most days.
Extra active
1.9
Very hard training, endurance work or highly physical job.
Calorie target guide
Your calculated maintenance calories are a starting estimate. After using a target for 2 to 4 weeks, your real-world weight trend, hunger, energy levels and training performance can help you decide whether to adjust.
Goal
Starting target
Notes
Maintain weight
Estimated maintenance calories
Useful as a starting point if your weight is broadly stable.
Slow weight loss
Maintenance minus about 300 kcal/day
A gentler deficit that may be easier to sustain.
Moderate weight loss
Maintenance minus about 500–600 kcal/day
Often used for steady weight loss, but individual needs vary.
Gradual weight gain
Maintenance plus about 250–500 kcal/day
Commonly used when trying to gain weight or build muscle.
Note: A lower calorie number is not always better. Very restrictive diets can be hard to sustain and may increase the risk of poor nutrition, tiredness, binge-restrict cycles or weight regain.
Why estimates vary
Formula-based estimates cannot fully account for genetics, muscle mass, hormones, medication, health conditions, sleep, stress and daily movement.
Calories are not everything
Food quality matters too. Protein, fibre, fruit, vegetables, wholegrains and healthy fats can affect fullness, health and long-term adherence.
Track trends, not one day
Body weight naturally fluctuates. Look at the trend over several weeks rather than changing your target based on one or two weigh-ins.
Practical advice
How to use your result sensibly
Treat your result as a starting point, not a rule. If your weight is stable for several weeks, your real maintenance intake is probably close to what you are currently eating. If your weight is changing, your real energy balance is different from your estimate.
For weight loss
Start with a moderate deficit rather than an extreme one.
Prioritise protein, fibre and minimally processed foods.
Keep some foods you enjoy so the plan is sustainable.
Review your trend after 2 to 4 weeks.
For weight gain or muscle gain
Use a small surplus if you want gradual gain.
Combine enough calories with resistance training.
Include protein-rich meals across the day.
Adjust slowly if weight is not changing after a few weeks.
When to get advice
Speak to a professional before dieting if you
Are pregnant, breastfeeding or under 18.
Have diabetes, kidney disease, heart disease or another medical condition.
Take medication affected by food intake or weight change.
Have an eating disorder or suspected eating disorder.
Seek help if you notice
Unplanned weight loss or rapid weight gain.
Extreme tiredness, dizziness or fainting.
Loss of periods, hair loss or feeling cold all the time.
Anxiety, guilt or loss of control around food.
Daily calorie needs FAQs
What are daily calorie needs?+
Daily calorie needs are an estimate of how many calories your body uses in a day. This includes energy used at rest, digestion, movement and exercise.
What is maintenance calories?+
Maintenance calories are the estimated number of calories you need each day to keep your weight broadly stable, assuming your activity level stays similar.
What is BMR?+
BMR stands for basal metabolic rate. It is an estimate of how many calories your body uses at rest for essential functions such as breathing, circulation and cell repair.
How does this calorie calculator work?+
This calculator estimates BMR using the Mifflin-St Jeor equation, then multiplies it by an activity factor to estimate daily maintenance calories.
How many calories should I eat to lose weight?+
A common approach is to create a moderate calorie deficit. NHS guidance says the average person trying to lose weight should aim to reduce daily calorie intake by about 600 kcal. Individual needs can vary.
How many calories should I eat to gain weight?+
For gradual weight gain, some people use a small calorie surplus, such as 250 to 500 kcal above maintenance. The right amount depends on your goal, training, appetite and health.
Is this calculator accurate?+
It is an estimate, not a precise measurement. Real calorie needs vary because of body composition, genetics, hormones, health conditions, medication, daily movement and tracking accuracy.
Who should get professional advice before changing calories?+
Speak to a GP, dietitian or qualified healthcare professional if you are pregnant, under 18, have an eating disorder or suspected eating disorder, have a medical condition, are losing weight unexpectedly, or plan a very low-calorie diet.
This page provides general health information and should not replace advice from a GP, pharmacist, dietitian or other qualified healthcare professional.
The calculator uses the Mifflin-St Jeor equation to estimate BMR and applies an activity multiplier to estimate maintenance calories. Calorie guidance should be reviewed against current public health and clinical advice before publication.
Last reviewed by AllHealthandCare editorial team: September 2026.
Next review due: September 2027.
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