Calorie calculator:
kg or stone, cm or feet.

Work out your daily calories

How the calculator works

It starts with resting energy: the calories your body uses in a day at rest. It works that out with the Mifflin-St Jeor equation, one of the most widely used formulas for adults:

• Men: 10 x weight in kg, plus 6.25 x height in cm, minus 5 x age, plus 5.
• Women: 10 x weight in kg, plus 6.25 x height in cm, minus 5 x age, minus 161.

Resting energy times an activity factor gives your maintenance calories, the amount that keeps your weight steady (often called TDEE, total daily energy expenditure).

Then your goal moves it, by amounts that are easy to stick to rather than fast:

• Lose fat: about 0.5% of your body weight a week. That is never more than 20% under maintenance, and never below 1,200 kcal a day for women or 1,500 kcal for men.
• Maintain: your maintenance number.
• Build muscle: about 0.25% of your body weight a week, which is 150 to 350 kcal a day over maintenance. Gaining faster than that is mostly fat.

The macro split gives protein first (2 g per kg of body weight when you are losing fat, 1.8 g per kg otherwise), fat at a quarter of your calories and at least 0.6 g per kg, and carbs for the rest. For protein in more detail, use the protein calculator.

A worked example

A 30 year old man, 180 cm and 80 kg, who trains 3 to 5 days a week and wants to lose fat:

1. Resting energy: 800 + 1,125 minus 150 + 5 = 1,780 kcal.
2. Maintenance: 1,780 x 1.55 = 2,759, so about 2,760 kcal a day.
3. Losing 0.5% of 80 kg is 0.4 kg a week. At about 7,700 kcal per kg of body weight, that is 440 kcal a day under maintenance: about 2,320 kcal a day.
4. Macros: 160 g protein, 64 g fat and about 275 g carbs.

Working in stone and feet? 1 stone is 6.35 kg, 1 pound is 0.454 kg and 1 inch is 2.54 cm, so 12 st 8 lb is 80 kg near enough and 5 ft 11 in is 180 cm. The calculator converts for you.

How accurate is it?

Any formula is a first guess. Two people of the same age, height and weight can burn a few hundred calories a day apart. Use the number for 2 to 3 weeks while you log your food and weigh in, then let your weight trend tell you the rest: if the average isn't moving the way you want, change your target by 100 to 200 kcal.

Your weight can swing by 1 to 2 kg from one day to the next with water, salt and food in your gut, so watch the weekly average rather than any single weigh-in. New to logging? How to count calories walks through labels, weighing and eating out.

Who should talk to a professional first

• Under 18s. This calculator is for adults. Talk to your GP before cutting calories.
• Pregnant or breastfeeding. Your needs are different: ask your midwife, GP or health visitor.
• Anyone with a history of an eating disorder. Counting calories can make things worse. Talk to your GP, or contact Beat, the UK eating disorder charity.
• Medical conditions or medication that affect your weight. Ask your GP or a registered dietitian.

This is a general estimate, not medical advice.

Hitting the number, day to day

Knowing your number is the easy part. In Physiqo, Ari sets your calorie, protein, steps and sleep targets and a goal (cut, bulk, maintain or recomp), and you log food by typing what you ate, a photo of the plate, a barcode or a screenshot. Ask how much protein have i got left today and she answers with the figure. The calorie counter app guide shows how it works, with UK foods checked first.

Plans and availability

Physiqo is £14.99 a month, £29.97 for 3 months or £95.88 for 12 months, after a free trial whose length the App Store sets. There is no free plan. Pricing, the free trial and how to cancel

Physiqo is coming soon to iPhone. Join the waitlist and you'll get one email the day it's on the App Store.

Last updated: 31 October 2026