Protein Intake Calculator
Estimate your daily protein needs based on your weight, activity level and goals, referenced against the UK Reference Nutrient Intake (RNI) and published sports-nutrition ranges.
Research suggests older adults may benefit from more protein than the standard UK reference value, to help offset age-related muscle loss. The 1.2g/kg figure used here is research/international guidance, not the official UK RNI — SACN’s UK RNI remains 0.75g/kg for all adults, including those over 65.
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Practical illustrative ranges for your entered weight across each activity level — not official UK recommendations — so you can see where your selection sits.
Approximate Protein in Common Foods
Typical values per 100g (cooked, where relevant) — actual values vary by brand, cut and preparation, so check packaging where precision matters.
Protein Intake Calculator UK
Our Protein Intake Calculator estimates how much protein you might need each day, based on your body weight, activity level and goals. It’s referenced against the official UK Reference Nutrient Intake (RNI) as well as published sports-nutrition guidance for active people, so you can see both the baseline requirement and a range appropriate to your activity level.
The UK Reference Nutrient Intake for Protein
The UK’s Reference Nutrient Intake (RNI) for protein is 0.75g per kilogram of body weight per day for healthy adults, set by the Committee on Medical Aspects of Food Policy (COMA) in 1991 and upheld by the Scientific Advisory Committee on Nutrition (SACN). The RNI is a population reference value designed to meet the requirements of nearly all healthy adults (defined as enough for about 97% of the population) — it isn’t necessarily an optimal target for people who are very active, trying to build muscle, or managing their weight, whose needs the RNI wasn’t designed to reflect.
How Much Protein Do Active People Need?
The International Society of Sports Nutrition’s position stand on protein and exercise (Jäger et al., 2017) concludes that overall daily protein intakes in the range of 1.4–2.0g per kg of body weight are sufficient for most people exercising regularly to build or maintain muscle, and that the evidence reviewed does not indicate this level of intake is detrimental to kidney function or bone metabolism in healthy, active people. The following are practical illustrative ranges for different goals and training types; individual requirements can vary.
- Endurance exercise (running, cycling, swimming): typically around 1.0–1.6g/kg, depending on training intensity and duration.
- Strength and resistance training: typically around 1.6–2.0g/kg.
- Weight loss with resistance training: research suggests intakes toward the higher end of this range, sometimes more, may help preserve lean muscle mass during a calorie deficit. Some sports-nutrition research in resistance-trained individuals during aggressive calorie deficits has looked at even higher intakes (around 2.3–2.8g/kg or more), though this is a more specialised finding rather than something most people need to aim for.
Protein Needs for Older Adults
Muscle mass and strength naturally decline with age (sarcopenia), and research suggests older adults may need more protein than the standard RNI to help offset this. Some academic reviews of UK nutritional requirements have proposed an increased reference intake of around 1.2g/kg/day for adults over 65, though this has not been formally adopted as the official UK RNI, which remains 0.75g/kg for all adults. This calculator reflects the higher, research-based figure when you select “aged 65 or over” for the general health category.
How to Use the Protein Intake Calculator
- Choose your units — metric (kg) or imperial (stone and pounds).
- Enter your weight.
- Select the activity level or goal that best matches your situation.
- Tick the age 65+ box if it applies, to see the age-adjusted general health range.
- Click Calculate to see your estimated daily protein range, how it compares to the UK RNI, a rough per-meal guide, and a comparison across all categories.
Is a High-Protein Diet Safe?
For healthy adults with normal kidney function, protein intakes in the ranges discussed above are generally considered safe as part of a balanced diet. However, protein needs are different for people with kidney disease: because the kidneys process the waste products of protein breakdown, high intakes can put extra strain on kidneys that are already impaired, and NHS kidney dietitians typically recommend a carefully managed, sometimes lower, protein intake for people with chronic kidney disease. If you have kidney disease, or any other condition that affects how your body handles protein, please speak to your GP or a registered dietitian rather than using general calculators like this one to set your intake.
Protein Distribution Through the Day
For most people, total daily protein intake matters more than precise timing. That said, some research suggests distributing protein across 3 to 4 meals — rather than concentrating it in one — may support muscle protein synthesis somewhat more effectively than the same total eaten in one or two sittings, with roughly 20–40g (or about 0.25g/kg) of high-quality protein per meal sometimes cited as a practical guide rather than a requirement.
Frequently Asked Questions
How much protein do I actually need per day?
It depends on your weight, activity level and goals. The UK RNI reference value is 0.75g per kg of body weight per day, a population reference designed to meet the requirements of nearly all healthy adults. Active people, those building muscle, and people losing weight while trying to preserve muscle may need more than the UK RNI, with the appropriate amount depending on the activity and goal. Use the calculator above for a range tailored to your situation.
Can eating too much protein be harmful?
For healthy adults with normal kidney function, protein intakes within the ranges discussed on this page are generally considered safe as part of a balanced diet, and excess protein your body doesn’t use is broken down and excreted or used for energy rather than accumulating harmfully. However, people with kidney disease need individualised protein guidance, since impaired kidneys may struggle to process protein waste products efficiently — this is a case where general calculators are not a substitute for advice from your GP or a registered dietitian.
Do I need more protein if I’m trying to lose weight?
Many people benefit from a higher protein intake during weight loss, since it can help preserve lean muscle mass while in a calorie deficit and may support feelings of fullness. Research in resistance-trained individuals suggests protein intakes toward the higher end of typical sports-nutrition ranges, and sometimes beyond, may be particularly helpful for muscle retention during aggressive calorie deficits, though total calorie balance remains the main driver of weight change.
Is animal or plant protein better?
Both can meet your protein needs. Animal proteins (meat, fish, eggs, dairy) contain all essential amino acids in one source, while many plant proteins are lower in one or more essential amino acids individually, though eating a variety of plant sources across the day (such as legumes, grains, nuts and soy foods) can provide a full amino acid profile. Neither is required for adequate protein intake, and a mixed or plant-based diet can both work well with appropriate planning.
Does protein timing matter as much as total intake?
Total daily protein intake appears to matter more than precise timing for most people. That said, some research suggests spreading protein across 3 to 4 meals, with roughly 20-40g per meal, may support muscle protein synthesis somewhat more effectively than eating the same total in one or two large meals — a reasonable practical approach rather than a strict rule.
Should I use protein supplements to hit my target?
Most people can meet even higher protein targets through food alone with some planning, but protein powders and shakes can be a convenient way to fill gaps, particularly for very active people with high requirements or limited time to prepare food. They are a supplement to a varied diet, not a replacement for one, and aren’t necessary for everyone.