Calorie Deficit Calculator

Enter your details to figure out how many calories you should be eating per day to either maintain or lose weight.

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Estimated daily calories

To maintain weight:

To lose weight:

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We have over 20 years of experience helping people reach their goal weight. Enter your email below for help and advice on meeting your calorie needs

This calculator offers an approximate caloric intake based on various factors, it’s important to note that individual nutritional requirements can differ.

Reviewed By Bariatric Dietician Heather Fry BSC (Hons)

Last Reviewed 19/03/2025

To lose weight you should be in a calorie deficit. This means eating less calories than what you use. This forces your body to use its stored energy (fat) and therefore you can lose weight. For example, if you burn 2,000 calories a day but eat 1,500 calories, you would be in a 500-calorie deficit. When you are in a calorie deficit, it is important to meet your protein requirements and have a balanced diet to avoid losing muscle and becoming malnourished. Start your journey by working out your healthy weight depending on your gender and height, this will give you a goal to work towards.

You may want to lose some weight before your surgery or embark on a new diet plan. Our calorie deficit calculator will make it easier to understand your daily calorie requirements to achieve this. The calculator relies on the Mifflin-St Jeor equation and should be used as a guide.

It is important to note, that after bariatric surgery your daily calorie intake is likely to be lower than this. Our specialist bariatric team will be able to advise you further of your requirements after surgery.

Tracking calories with precision can be challenging, but following some general guidelines can help you get a better sense of your daily intake. Here are some simple strategies to assist you:

Check Labels on Store-Bought Foods

Food labels typically provide calorie information per portion, per 100g, and per package. Per-portion data is often more practical, but keep in mind that your portion sizes may differ from those suggested by the manufacturer. This variance can significantly impact your total daily calorie consumption.

Weigh Your Portions

Initially, weighing your food portions can be very helpful. It allows you to understand the calorie content of your meals and helps you decide if you need to adjust portion sizes.

Keep a Food Diary

Recording everything you eat and drink each day can simplify calorie tracking. Try maintaining a food diary for a week or two to gauge your calorie intake accurately. If you find it beneficial, continue this practice.