Free Calorie Calculator.
Use our free Calorie Calculator to estimate daily calories for maintenance, weight loss or weight gain based on age, sex, height, weight and activity level.
Calorie Calculator
Estimate your daily calorie needs for maintenance, weight loss or weight gain using your age, sex, height, weight and activity level.
Calorie Calculator Online
Use this Calorie Calculator to estimate how many calories you may need each day to maintain your weight, lose weight or gain weight. Enter your age, sex, height, weight and activity level to get an instant estimate.
This tool is designed for adults aged 18+ and gives a practical daily calorie estimate rather than a medical diagnosis. Daily calorie needs vary from person to person, but age, weight, height and activity level are all important factors. The NHS says average needs are around 2,500 kcal a day for men and 2,000 kcal a day for women, although individual needs can be higher or lower depending on circumstances.
How this calorie calculator works
This calculator first estimates your BMR (Basal Metabolic Rate), then adjusts that figure using an activity factor to estimate your daily maintenance calories. For the BMR step, the calculator uses the Mifflin-St Jeor equation, a widely cited predictive equation for resting energy expenditure. A later comparison study found that it was the most reliable of the equations they assessed among many adults.
Your result then shows:
- Estimated BMR — calories your body may burn at rest
- Maintenance calories — calories to roughly maintain your current weight
- Mild weight loss calories — a smaller calorie reduction
- Weight loss calories — a larger reduction below maintenance
- Weight gain calories — calories above maintenance
These are estimates, not guarantees. Even authoritative health sources note that calorie needs differ between individuals, and can be affected by activity, metabolism and other factors.
How to use the calculator
- Choose your sex.
- Enter your age.
- Enter your height in cm.
- Enter your weight in kg.
- Select your activity level.
- Read the estimated calorie targets instantly.
Use the Reset button to return to the default values.
What is BMR?
BMR stands for Basal Metabolic Rate. It is an estimate of the energy your body uses each day at rest to support basic functions, such as breathing and circulation. From there, calorie calculators apply an activity multiplier to estimate total daily needs. This is broadly consistent with how established calorie-planning tools frame daily energy needs.
What are maintenance calories?
Your maintenance calories are the estimated number of calories you would need per day to keep your weight roughly the same. The NHS notes that calorie needs vary depending on factors such as age, weight, height and how much exercise you do.
How many calories should I eat to lose weight?
For many adults, a modest calorie deficit is often used for weight loss. NHS guidance says that when trying to lose weight, the average person is often advised to reduce daily intake by around 600 kcal, though this is still a general guide rather than a universal rule.
This calculator shows a mild weight-loss target and a more practical weight-loss target to give you a wider range. Sustainable weight management generally works better when the plan is realistic and can be maintained over time. NIDDK also emphasises that long-term success comes from a healthy eating plan and regular physical activity that you can stick with.
Example calorie estimates
Example 1: Moderately active adult
A 30-year-old male, 175 cm tall, weighing 70 kg, with a moderately active lifestyle, will usually see maintenance calories above his BMR, because activity increases daily energy needs.
Example 2: Weight loss estimate
A user who wants to lose weight can compare the maintenance results with the weight-loss targets to decide on a practical starting point.
Example 3: Weight gain estimate
Someone trying to gain weight can use the weight-gain result as an estimate of a calorie surplus above maintenance.
Important notes before using the result
This calculator is best used as a starting estimate. It should not replace professional advice. You should be especially cautious about relying on a general calorie calculator if you:
- are under 18
- are pregnant or breastfeeding
- have an eating disorder
- have a medical condition that affects weight, appetite or nutrition
For more personalised guidance, authoritative health organisations point users toward structured calorie and weight-planning tools and professional support where needed.
Frequently asked questions
What does this calorie calculator estimate?
It estimates your BMR and daily calorie needs for maintenance, weight loss, and weight gain based on your age, sex, height, weight, and activity level.
Is the calorie result exact?
No. It is an estimate. Calorie needs vary between individuals and can change with activity, body composition, metabolism and health status.
Can I use this calorie calculator for weight loss?
Yes, as a starting point. The calculator gives estimated calorie targets below maintenance levels, but long-term weight loss should be approached sensibly and may require professional support.
Does activity level affect calorie needs?
Yes. More activity usually increases the number of calories your body needs to maintain weight.
Is this calorie calculator suitable for children?
No. This version is designed for adults aged 18 and over. Children and teenagers have different nutritional needs, so they should not rely on a general adult calorie calculator.
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