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Calorie & Protein Calculator

Find your estimated daily calorie and protein targets to support healthy, sustainable weight loss.

Everyone's calorie needs are different. Enter a few details below to estimate how much energy your body uses each day and find a practical starting point for your nutrition goals.

  • Free to use
  • No account required
  • Results calculated instantly

Your details

About you

Sex used for calculation

The standard equation uses different constants for males and females. If neither estimate is appropriate for you, a healthcare professional can help assess your energy needs.

Age

Height

Current weight

How active are you?

Activity levels are broad estimates rather than precise measurements. If you are unsure, choose the lower option. Picking a higher level only to get a larger allowance makes the estimate less useful.

Choose your daily deficit

A smaller deficit can be easier to sustain. Choose an approach that allows you to meet your nutritional needs.

Your estimated daily targets

Calorie target

Enter your age, height and weight and choose how active you are to see your targets.

Estimated maintenance

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Calories to maintain your current weight.

Suggested protein goal

—

A daily range to help protect muscle.

This calculator provides general estimates for adults and is intended for educational purposes. It does not replace personalised advice from a healthcare professional. Calorie and protein requirements may differ depending on your health, medication, body composition and nutritional needs.

If you are pregnant, breastfeeding, have kidney disease, diabetes requiring medication that can cause low blood sugar, a history of eating disorders or concerns about inadequate nutrition, seek professional advice before following a calorie-restricted diet.

Want more support with your weight loss?

Our UK pharmacists can check whether a medical weight-loss treatment could be suitable for you, alongside diet and activity.

Start free consultationExplore our weight-loss service

Your results explained

Understanding your results

The calculator gives you three starting points. Here is what each one means and how to use it.

Your calorie target

Your body uses energy throughout the day, even while resting. The amount you need depends on factors such as your age, weight, height and physical activity.

Your maintenance calories are an estimate of how much energy your body needs to maintain its current weight. Weight loss generally requires an ongoing calorie deficit, meaning you consume less energy than you use.

A moderate deficit is often easier to maintain than a highly restrictive diet. Day-to-day weight also moves with fluid balance, and your energy use changes as your weight changes, so progress is rarely a straight line.

Why protein matters

During weight loss, the body can lose muscle as well as fat. Adequate protein, together with appropriate physical activity and resistance exercise, can help support muscle maintenance.

Protein-rich foods include chicken, fish, eggs, yoghurt, cottage cheese, tofu, beans and lentils.

If your appetite is reduced, prioritising nutritious, protein-containing foods can make it easier to meet your daily requirements.

Monitoring progress

Your results are estimates rather than exact instructions. Try to follow a balanced dietary pattern and assess your progress over several weeks.

Weigh yourself under consistent conditions and look at the overall trend rather than daily fluctuations.

If your weight is not changing as expected after around 3 to 4 weeks, review your food intake, activity and anything else that may affect your weight. You may benefit from discussing your results with a healthcare professional. As your weight changes, your energy needs may change too.

Protein on your plate

What your protein range looks like

Approximate protein in everyday foods, to help you plan meals that reach your daily range. Building each meal around one or two of these makes it much easier.

Values are approximate and vary by brand and how food is prepared. Check food labels for exact amounts.

  • ~30gChicken breast100 g, cooked
  • ~25gTinned tuna1 small tin, drained
  • ~22gSalmon fillet100 g, cooked
  • ~15gGreek yoghurt, 0% fat150 g pot
  • ~13gEggs2 medium
  • ~12gFirm tofu100 g
  • ~10gCottage cheese100 g
  • ~10gBaked beansHalf a 415 g tin

Eat well

Practical nutrition advice

These principles follow the NHS Eatwell Guide. They are general guidance rather than a fixed meal plan, so adapt them to your own needs, preferences and any advice from your healthcare team.

  • Include protein at meals

    Chicken, fish, eggs, yoghurt, cottage cheese, tofu, beans and lentils all count. Spreading protein across the day is easier than eating it in one go.

  • Eat a variety of vegetables and fruit

    Aim for at least 5 portions a day. Fresh, frozen, tinned and dried all count.

  • Choose fibre-rich carbohydrates

    Wholegrain bread, pasta and rice, oats, potatoes with skins and pulses help you feel fuller and support digestion.

  • Include healthy fats in sensible amounts

    Choose unsaturated oils and spreads, nuts and seeds, and oily fish. Fats are energy-dense, so small portions go a long way.

  • Drink enough fluids

    Around 6 to 8 glasses a day. Water, lower-fat milk and sugar-free drinks are good choices.

  • Aim for a pattern you can keep

    A way of eating you enjoy and can stick to will do more over time than a strict plan you abandon.

  • Be active in ways that suit you

    Regular movement helps, and resistance or strength exercise, where appropriate for you, helps you keep muscle while losing weight.

  • Do I need to skip meals?

    No. You do not need to skip meals or eat only once a day to lose weight.

    If your appetite is reduced, smaller meals may be more manageable.

Your overall pattern matters most

What matters is your overall dietary pattern and whether your energy intake is appropriate for your needs. Regular, balanced meals can help you obtain enough protein, fibre, vitamins and minerals.

When your appetite is reduced

Eating less food overall makes each meal count for more. If you are not very hungry, it is easy to fall short on protein, fibre, vitamins and minerals without noticing.

Start meals with the protein and vegetables on your plate, keep simple nutritious snacks to hand, and keep drinking regularly. If you are regularly struggling to eat enough, speak to a healthcare professional.

Weight loss with Totiva

Calories are only part of the picture

If you have been trying to lose weight for a while, our pharmacist-led weight-loss service may help. Complete a free online consultation and a prescriber will review whether treatment is suitable for you.

Start free consultationExplore weight loss
  • Free online consultationAnswer a few questions about your health. You only pay if treatment is approved.
  • Reviewed by a prescriberA UK prescriber checks your health history before anything is prescribed.
  • Pharmacist support throughoutMessage our pharmacy team about dose changes, side effects or your nutrition.

Frequently asked questions about calories and protein

Our method

How we calculate your targets

Resting energy is estimated with the Mifflin–St Jeor equation, using your actual weight. We multiply that by an activity factor to estimate maintenance calories, then subtract the deficit you choose.

Protein uses 1.2 to 1.6 g per kilogram. At a BMI of 30 or above we use an adjusted weight: the weight at a BMI of 25 for your height, plus a quarter of the difference to your current weight. This is a practical approach, not a universally agreed standard, and protein estimation methods vary.

We do not suggest a calorie target if the result would be low, if your BMI is below 18.5, or if you are aged 75 or over. In those cases we recommend speaking with a healthcare professional.

Your details stay in your browser. We do not store or send the measurements you enter.

Clinical references

  1. Mifflin MD, St Jeor ST, et al. (1990). A new predictive equation for resting energy expenditure in healthy individuals. (opens in a new tab)
  2. NICE guideline NG246: Overweight and obesity management. (opens in a new tab)
  3. Nutritional priorities to support GLP-1 therapy for obesity: a joint advisory (2025). (opens in a new tab)
  4. NHS: The Eatwell Guide. (opens in a new tab)

These sources inform the approach. NICE, the NHS and the authors listed have not reviewed or endorsed this calculator or its adjusted-weight protein method.

When to get personal advice first

This calculator is general adult nutrition education, not an individual dietetic assessment. The standard equations can also be less reliable for some body compositions and health conditions. Speak to a healthcare professional before following a calorie-restricted diet if:

  • You are pregnant or breastfeeding
  • You have kidney disease or have been told to limit protein
  • You have an eating disorder or a history of disordered eating
  • You have type 1 diabetes
  • You take insulin or a sulfonylurea, where changing what you eat can affect the risk of low blood sugar
  • You are frail, malnourished or have lost weight without trying
  • You are aged 75 or over
  • You already find it hard to eat enough

Want to talk through your nutrition? You can contact our pharmacy team.

Medically reviewed by

Callum Armstrong

Callum Armstrong

Superintendent PharmacistGPhC: 2220517

This page has been reviewed by our clinical team to ensure it is clear, accurate, and up to date.

Last updated: