Protein calculator

Your protein needs are unique to you. The amount of protein you need depends on things like your age, sex, weight, activity levels, and health goals.

Our protein calculator helps you understand how much protein your body may need each day. It gives you a personalised daily target that you can use to guide your eating habits.

In this guide, we explain how daily protein requirements work and how you can use your result to plan what you eat.

Medically reviewed by

Dr Kathryn Basford

Last reviewed: 30 Jan 2026

What's on this page?

1. Why is protein important in your diet?
2. How much protein do you need per day?
3. How our protein calculator works
4. Recommended protein intake by goal
5. Do you need more protein if you exercise?
6. How to meet your protein target (without supplements)
7. Frequently asked questions

Why is protein important in your diet?

Protein is a key nutrient that helps your body repair, grow and stay healthy. It supports things like:

muscle mass
hormone production (hormones are your body’s chemical messengers)
enzyme production (proteins that speed up chemical reactions in your body)
immune function
the health of your skin and hair
repairing the body after injury
pregnancy

Discover the benefits of high protein foods for weight loss.

Protein is made up of amino acids. Some are “essential”, which means your body cannot make them by itself, so you need to get them from food.

Getting enough protein becomes particularly important when you’re:

keeping active
losing weight
trying to build muscle

It helps protect your lean mass, supports recovery, and increases fullness.

Research also shows that muscle mass gradually declines from the third decade of life and accelerates after age 50. This is because the body becomes less responsive to dietary protein. As you get older, you will need to eat slightly more protein, spread across meals, to stimulate how your muscles repair and grow.

"Protein plays a vital role in supporting your muscle health, metabolism and overall wellbeing. Your needs change depending on your weight, activity level and goals, so it’s important to adjust your intake accordingly.”

How much protein do you need per day?

For healthy adults, UK protein recommendations are based on body weight. The recommended nutritional intake (RNI) is 0.75g of protein per kg of body weight per day, which helps prevent deficiency. This works out at around 56g per day for men (based on a body weight of 75kg) and 45g per day for women (based on 60kg).

Many adults can benefit from eating more than their recommended protein intake. Evidence summarised in expert reviews shows that intakes around 1.2 to 2 g per kg bodyweight per day can support lean mass and strength in healthy, active adults. Also, if you are doing strength training, eating around 1.6g of protein per kg of body weight each day supports muscle growth. This shows that your protein needs change with your activity level.

As we age, our muscles respond less strongly to protein, so older adults often need a little more to support strength.

Protein intake can therefore vary considerably beyond general guidelines. By using tools like our protein calculator, you can find a target protein intake that’s personalised to you.

Learn how to incorporate protein into your diet in our 7-day plan.

How our protein calculator works

Our protein calculator helps you create a personalised daily protein target (in grams) based on the following criteria:

weight
age
sex
activity level (sedentary, moderately active, or very active)
goals (weight loss, muscle gain, or maintenance)

It gives you a daily target that supports weight maintenance, fat loss or muscle gain.

Important: Your results are intended to guide healthy eating choices but should not replace any medical advice you’ve been given by a doctor or be used to diagnose nutrient deficiencies. If you have a medical condition affecting your nutritional needs, speak to a GP or dietitian.

Recommended protein intake by goal

Your protein needs will vary based on what you’re trying to achieve. Here we explore protein intake considerations based on 3 common goals: weight loss, muscle growth, and maintenance.

Weight loss

Increasing your protein intake as part of a balanced diet can help reduce hunger, make you feel fuller and support your muscle mass when you are trying to lose weight.

Studies show that eating 1.2 to 1.6g/kg/day of protein can reduce fat mass while helping preserve lean mass. This is important because during weight loss, your body tends to break down both fat and muscle. Eating more protein helps you keep your muscle while you lose weight.

The same research also shows that higher-protein diets increase thermogenesis (the energy you burn digesting food). This helps to prevent weight regain by stabilising appetite and maintaining fat-free mass. A higher protein intake may therefore help support consistent, long-term weight loss.

However, protein alone does not cause weight loss – a calorie deficit is still needed for safe and consistent results. Like protein intake, calorie deficit also varies from person to person. You can use our Calorie Deficit Calculator to get a personalised calorie target for weight loss.

Whether you're losing weight through lifestyle changes or weight loss treatment, getting enough protein can help protect muscle while your body weight changes.

Muscle gain

Research shows that muscle growth is most effectively supported when your daily protein intake is around 1.6g per kg of body weight per day, alongside resistance training. A large meta analysis found this to be the point where gains in lean mass start to level off. While higher intakes are sometimes used in practice, evidence suggests that amounts above this level do not consistently provide additional benefit for most people.

Getting enough protein ensures your muscles have the amino acids needed for repair and growth after training. Evidence also shows that, in healthy adults, these higher protein intakes are considered safe, so long as they fit within a balanced diet.

Healthy maintenance

If you're not trying to change your weight, 0.75 to 1.2g per kg of body weight per day is an appropriate amount of protein for most adults.

Older adults may benefit from aiming closer to 1.0 to 1.2g per kg of body weight per day, which research suggests can help maintain muscle strength. This helps counteract the gradual loss of muscle that happens as you get older.

Do you need more protein if you exercise?

Regular training increases how much muscle your body breaks down and repairs, meaning you need more amino acids to repair and rebuild muscle tissue.

Moderately active adults can use 0.75g/kg/day as a baseline. If you exercise more frequently, sports nutrition guidelines recommend that protein intakes rise to 1.2 to 2.0g/kg/day.

Higher intakes, especially 1.6g/kg/day or above, are most useful for people who lift weights or take part in strength-based training, where muscle repair and growth are a priority.

If you train intensely or have a medical condition affecting nutrient absorption or energy needs, personalised advice from a GP or dietitian may be helpful.

How to meet your protein target (without supplements)

Most people can meet their protein goals through food alone. Examples include:

lean meats
poultry (chicken and turkey)
fish
eggs
dairy products (including cottage cheese and Greek yoghurt)
beans
lentils
chickpeas
tofu
nuts
other plant-based sources (tempeh, Quorn, seitan)

Protein supplements such as shakes and bars are optional and may be convenient, but they're not necessary for most people. Eating foods that are naturally high in protein can help improve fullness during weight loss and support muscle recovery after exercise. Meeting your protein needs through food also provides vitamins, minerals, and fibre that supplements do not offer.

For meal ideas to help you meet your protein goals, check out our guide to high-protein foods for weight loss.

Frequently asked questions

How much protein do I need to lose weight?

A helpful way to work out your protein needs for weight loss is to aim for 1.2 to 1.6g of protein per kg of your body weight per day.

Using UK average adult body weights as an example, a female weighing 72kg may need around 86 to 115g of protein per day to support weight loss, while a male weighing 85kg may need around 102 to 136g per day.

The higher end of this range may be more appropriate if you are active, lift weights, or want to preserve as much muscle as possible while eating in a calorie deficit. Eating more protein can also increase feelings of fullness, which can make appetite easier to manage during weight loss. However, higher protein intake alone does not lead to fat loss – you still need an overall calorie deficit to reduce body fat.

The calculator on this page gives you a personalised protein intake target for weight loss based on your sex, weight, age, activity level, and goals, helping you plan a calorie deficit while ensuring you get enough protein.

Is eating 100g of protein a day too much?

No, eating 100g of protein per day is not too much for most healthy adults. It fits comfortably within commonly used evidence-based intake ranges. How much you personally need depends on your weight, activity level and goals.

For example, many adults aiming for 1.2 to 1.6g/kg/day for weight loss or muscle maintenance will easily reach or exceed 100g.

Research examining the potential harms of higher protein intakes shows no strong evidence of kidney or bone damage in healthy adults. If you have kidney disease, speak to a GP for personalised advice.

How much protein should a 70kg adult consume per day?

For a 70kg adult, the UK minimum guideline is about 53g per day (0.75g/kg). However, many adults can safely consume more than their recommended intake, especially if they have a goal in mind. For example:

84 to 112g per day (1.2 to 1.6g/kg) is suitable for active adults or those looking to lose weight
112g per day or more (≥1.6g/kg) may support muscle gain, especially with resistance training.

Your ideal target depends on your goals and training routine, which is where our protein calculator can help.

What is the 50/30/20 rule for protein?

The 50/30/20 rule is a simple macro split some people use when planning meals. It typically means that 50% of your daily calories come from carbohydrates, 30% from fats and 20% from protein, although some versions adjust these ratios depending on individual goals.

This approach is not an official guideline or evidence-based recommendation, but it can offer a straightforward structure if you prefer planning by macronutrient ratios. If you follow it, your actual protein intake will depend on your calorie needs. Many adults who exercise or want to support muscle maintenance may require more protein than this framework provides.

How much protein do I need to lose fat but keep muscle?

To support fat loss while preserving muscle, most adults benefit from 1.2 to 1.6g of protein per kg of body weight per day. This range is especially helpful if you’re doing resistance training, because protein supplies the amino acids your body needs for muscle repair and maintenance during a calorie deficit.

Eating enough protein can also improve fullness, making it easier to maintain your calorie deficit over time. As long as you remain in that deficit, higher protein intake helps protect lean mass while your body reduces stored fat.

Is high protein safe long-term?

Higher protein intakes have not been shown to cause harm in healthy adults, based on current evidence. Many people choose to eat more protein to support appetite control, maintain muscle mass, or meet the demands of regular training

If you have kidney disease, diabetes with kidney involvement, or another medical condition affecting nutrient metabolism, you should speak to a GP or dietitian before increasing your protein intake. For most healthy adults, higher protein intake can be part of a balanced long-term eating pattern.

Medically reviewed by

Dr Kathryn Basford

Dr Kathryn Basford is a GP based in London. She graduated from the University of Manchester and completed her GP training through Whipps Cross Hospital in London. Outside of work she enjoys baking and keeping active, running marathons, swimming, and triathlons.

Last reviewed: 30 Jan 2026