Calories Per Day Calculator UK

Mifflin-St Jeor formula — NHS guidelines — Updated February 2026

TDEE & BMR Calorie Calculator

Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the most accurate Mifflin-St Jeor formula, with full macronutrient breakdown

Weight:
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Understanding Calories, BMR & TDEE

Knowing how many calories your body needs each day is the foundation of effective weight management. Our calculator uses the Mifflin-St Jeor equation, the most widely validated formula in clinical nutrition research.

The Mifflin-St Jeor Formula

Developed in 1990, the Mifflin-St Jeor equation is considered more accurate than the older Harris-Benedict equation for most people, particularly in the context of modern, more sedentary lifestyles.

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

Activity Level Multipliers

Activity Level Multiplier Description
Sedentary1.2Desk job, little or no formal exercise
Lightly Active1.375Exercise 1–3 days/week (walking, light gym)
Moderately Active1.55Exercise 3–5 days/week (jogging, cycling, gym)
Very Active1.725Hard exercise 6–7 days/week (running, sport)
Extra Active1.9Physical job + exercise, or twice-daily training

NHS Dietary Guidelines for the UK

The NHS Eatwell Guide provides the most up-to-date dietary recommendations for adults in England. Key points include:

  • Eat at least 5 portions of fruit and vegetables every day (a portion is 80g of fresh, frozen, or tinned fruit or vegetables)
  • Base meals on higher-fibre starchy carbohydrates such as potatoes with skin, wholemeal bread, and brown rice
  • Have some dairy or dairy alternatives (choose lower-fat and lower-sugar options where possible)
  • Eat beans, pulses, fish, eggs, meat, and other proteins — aim for at least 2 portions of sustainably sourced fish per week, one of which should be oily
  • Choose unsaturated oils and spreads, and eat in small amounts
  • Drink 6–8 cups or glasses of fluid daily — water, lower-fat milk, and sugar-free drinks all count
  • Cut down on foods and drinks high in fat, salt, and sugar
  • Men should consume no more than 14 units of alcohol per week, spread across 3+ days

Traffic Light Food Labels

The UK's voluntary traffic light food labelling system makes it easy to make healthier choices at a glance. Labels display energy (kcal), fat, saturated fat, sugar, and salt content per serving, colour-coded as:

RED

HIGH — Eat less often or in smaller amounts

AMBER

MEDIUM — Enjoy as part of a balanced diet

GREEN

LOW — A healthier choice

Ultra-Processed Foods and UK Health

Ultra-processed foods (UPFs) now make up approximately 57% of the calories in the average UK adult diet, according to research published in the British Medical Journal. UPFs are industrial food formulations typically containing five or more ingredients, including additives not found in home cooking — such as emulsifiers, flavour enhancers, and colourings. Studies published in The Lancet (2024) have linked high UPF consumption to increased risks of cardiovascular disease, type 2 diabetes, depression, and certain cancers. The NOVA food classification system categorises foods from Group 1 (unprocessed) to Group 4 (ultra-processed). The NHS recommends prioritising whole and minimally processed foods, and reading labels to identify UPF ingredients.

Calorie Counting: Accuracy and Limitations

While calorie counting is a useful tool, it is important to understand its limitations. UK food labelling regulations allow a tolerance of up to 20% in the declared calorie content of packaged foods. Cooking methods significantly affect calorie availability — for example, cooked rice has more bioavailable calories than raw, and resistant starch in cooled cooked potatoes is metabolised differently. Individual gut microbiome differences mean two people can absorb different numbers of calories from the same food. Despite these limitations, maintaining a calorie deficit through consistent tracking remains one of the most evidence-based approaches to weight loss. Apps such as Nutracheck (widely used in the UK), MyFitnessPal, and the free NHS Weight Loss Plan provide practical tools for tracking.

UK Obesity Statistics 2026

Obesity is a major public health challenge in the United Kingdom:

  • Around 28% of adults in England are obese (BMI ≥30), and a further 36% are overweight (BMI 25–30) (NHS Digital 2024).
  • Obesity costs the NHS approximately £6.5 billion per year in direct treatment costs.
  • The broader economic cost of obesity in the UK, including lost productivity, is estimated at £58 billion per year.
  • The UK has one of the highest rates of obesity in Western Europe, behind only Hungary and Turkey.
  • NHS weight loss drugs such as semaglutide (Wegovy/Ozempic) are now available through specialist weight management services for those with BMI ≥35 and at least one weight-related condition.

Frequently Asked Questions

How many calories should I eat per day?
NHS reference intakes are 2,000 kcal/day for women and 2,500 kcal/day for men. Your personal needs depend on age, sex, height, weight, and activity level. Use the Mifflin-St Jeor formula (used by this calculator) for an accurate estimate. For safe weight loss, the NHS recommends a deficit of no more than 500–600 calories per day.
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the calories your body needs at complete rest for basic functions. TDEE (Total Daily Energy Expenditure) is your total calorie burn including all activity — calculated by multiplying BMR by an activity factor from 1.2 (sedentary) to 1.9 (extra active). Eating at your TDEE maintains your current weight.
What are the NHS guidelines on daily calorie intake?
The NHS recommends 2,000 kcal/day for women and 2,500 kcal/day for men as population reference intakes used on food labels. The NHS Eatwell Guide advocates a balanced diet with 5+ fruit/veg portions daily, fibre-rich carbohydrates, protein, dairy, and limited fat, salt, and sugar.
How do I calculate macronutrients from my calorie target?
A standard split is 30% protein, 40% carbohydrates, 30% fat. Protein and carbs contain 4 kcal/g; fat contains 9 kcal/g. For a 2,000 kcal target: 150g protein, 200g carbs, 67g fat. Our calculator provides this breakdown automatically for each calorie goal.
What are ultra-processed foods and should I avoid them?
Ultra-processed foods (UPFs) are industrial formulations with additives not found in home cooking. They make up 57% of the average UK diet. Studies in The Lancet (2024) link high UPF consumption to cardiovascular disease, diabetes, and certain cancers. The NHS recommends prioritising whole, minimally processed foods.
How accurate is calorie counting for weight loss?
Food label calories can be off by up to 20%. Cooking methods and gut microbiome affect absorption. Despite limitations, maintaining a calorie deficit is the most evidence-based weight loss approach. Apps like Nutracheck, MyFitnessPal, and the free NHS Weight Loss Plan app help with practical tracking.
What are traffic light food labels in the UK?
UK traffic light labels display energy, fat, saturated fat, sugars, and salt per serving in red (high), amber (medium), or green (low). They help you make healthier choices at a glance. Used by Tesco, Sainsbury's, Waitrose, and other major UK supermarkets. Aim for mostly green and amber labels for a healthy diet.
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Mustafa Bilgic

Health data analyst at UK Calculator. Specialises in NHS-aligned nutrition and calorie calculators. Learn more.

Last updated: February 2026 | Based on NHS Eatwell Guide and Mifflin-St Jeor (1990) formula