Sex assigned at birth

Age (years)

Weight (kg)

Height

Activity level

Your goal

Please fill in all fields with valid values.

Your daily calorie target

Maintenance calories

2,150 kcal / day

Sample — enter your details

1,650

Lose

2,150

Maintain

2,450

Gain

Estimated macros

161g

Protein

215g

Carbs

72g

Fats

BMI

22.5

Healthy weight

How to Use the Calorie Calculator?

Fill in your details, press Calculate, and your personalised daily calorie target appears instantly on the right. Here is exactly what each field means.

Sex assigned at birth — the Mifflin-St Jeor formula uses different values for men and women.
Age — enter your age in years between 15 and 100.
Weight — enter in kilograms. If you only know your weight in stone, multiply by 6.35.
Height — use the cm or ft toggle. Average UK adult height is around 175 cm (5 ft 9) for men and 162 cm (5 ft 4) for women.
Activity level — be honest. Most desk workers fall under lightly active, even with 2 to 3 gym sessions per week.
Your goal — lose weight, maintain your current weight, or gain weight for muscle building.

Which Formula Does This Calorie Calculator Use?

This tool uses the Mifflin-St Jeor equation, the most accurate method for estimating Basal Metabolic Rate (BMR) according to nutrition researchers and registered dietitians across the UK. It is the formula closest to NHS dietary guidance and is preferred over older methods like Harris-Benedict.

Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5
Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161

Daily calories = BMR × Activity multiplier (1.2 to 1.9)

The result is your Total Daily Energy Expenditure (TDEE) — the number of calories your body actually burns each day. Everything else in your results flows from this number.

Understanding Your Results

Lose weight

Deficit of 500 kcal/day

Leads to roughly 0.5 kg of fat loss per week — the rate recommended by the NHS and the British Dietetic Association as safe and sustainable.

Maintain

Your TDEE

The number of calories to eat to stay exactly at your current weight. Your starting point for any diet plan.

Gain weight

Surplus of 300 kcal/day

A modest surplus suited to lean muscle gain when paired with resistance training. Keeps unnecessary fat gain low.

Macros

Protein · Carbs · Fats

Split at 30 / 40 / 30 percent, in line with the NHS Eatwell Guide. Adjust protein upward if you train regularly.

What your BMI result means

BMI uses your height and weight to give a rough indication of whether you are in a healthy weight range. NHS classifications: under 18.5 underweight, 18.5 to 24.9 healthy weight, 25 to 29.9 overweight, 30 and above obese. BMI does not account for muscle mass — use it alongside your calorie target, not instead of it.

Calorie Targets That Work for London Diets

Whether you are based in Croydon, South London, or anywhere across the borough, your calorie target is the same — what changes is how you hit it. For those following a halal diet, excellent protein sources include lamb, chicken, beef, eggs, lentils, and chickpeas — all widely available at local markets across Croydon, Brixton, and Tooting. Slow-digesting carbohydrates like brown rice, oats, and wholemeal bread keep energy stable through busy London days.

During Ramadan, the same daily calorie target applies — simply divide it across Suhoor and Iftar. Prioritising protein-rich foods at Suhoor helps maintain energy and reduce hunger through the fast. At Infusion Village we publish seasonal recipes, restaurant reviews across South London, and community food guides to help you eat well within your targets.

Frequently Asked Questions

How many calories should I eat per day in the UK?

The NHS recommends 2,000 kcal per day for women and 2,500 kcal per day for men as a population average. Your actual daily calorie needs depend on your age, height, weight, and how active you are. Use the calorie calculator above for a number based on your specific details — it takes about 30 seconds.

Is 1,500 calories a day enough to lose weight safely?

For many adults, yes — 1,500 kcal per day typically creates a calorie deficit that leads to steady weight loss. The NHS advises not going below 1,200 kcal per day for women or 1,500 kcal per day for men without medical supervision, as very low intakes can cause muscle loss and nutritional deficiencies. The calculator shows you a safe 500 kcal deficit from your personal maintenance figure.

How accurate is this calorie calculator?

The Mifflin-St Jeor equation is accurate to within approximately 10 percent for most non-obese adults, making it the most reliable publicly available formula. It is the method recommended most often by registered dietitians in the UK. For a fully personalised assessment — especially if you have a health condition or are pregnant — consult your GP or an NHS-registered dietitian.

This tool is for general informational purposes only and does not constitute medical or dietary advice. Always consult your GP or a registered dietitian before making significant changes to your diet. NHS reference intakes: 2,000 kcal/day for women, 2,500 kcal/day for men. Last reviewed June 2025. Sources: NHS Eatwell Guide, British Dietetic Association, Mifflin MD et al. (1990) Journal of the American Dietetic Association.