What this calculator works out
This calculator multiplies your body weight by a protein rate in grams per kilogram, then applies any extra allowance you choose. It returns a daily protein figure and shows the rate it used.
The rate is the whole calculation. Published figures range from the UK reference intake of 0.75 g per kg up to around 2 g per kg for people training hard, and choosing between them is a judgement rather than an arithmetic step.
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Before you choose a rate
- The UK Reference Nutrient Intake for adults is 0.75 g per kg of body weight per day. This is the amount that meets the needs of almost everyone in the population, not an optimum.
- Higher rates are commonly discussed for older adults, where around 1 to 1.2 g per kg is often suggested to help maintain muscle mass.
- People training seriously with weights or endurance sport often use 1.4 to 2 g per kg. Evidence of benefit above roughly 1.6 g per kg is thin.
- Use current body weight. Some sources use lean mass or a target weight instead, which produces a lower figure.
National diet survey data consistently shows average protein intakes well above 0.75 g per kg. Deficiency is rare in the UK outside specific clinical situations. The question for most people is not whether they get enough, but whether it is spread sensibly across the day.
How this calculator works
One multiplication and an optional uplift:
Daily protein = weight in kg × grams per kg × (1 + extra allowance ÷ 100)The extra allowance exists for situations where a temporary uplift is being applied — recovery from illness or injury, for instance — rather than as a general safety margin.
The calculator does not check whether the rate you entered is sensible, and it has no knowledge of kidney function, which is the main reason very high intakes are sometimes inadvisable.
Worked example: 75 kg at 1 g per kg
Using the default figures — 75 kg at 1 g per kg with no extra allowance:
- Daily protein: 75 × 1 = 75 g
- Rate used: 1 g/kg
For context, 75 g is roughly a chicken breast, two eggs, a tin of beans and a pot of Greek yoghurt across a day — reachable without supplements or much planning. At the UK reference intake of 0.75 g per kg the figure falls to 56 g; at 1.6 g per kg for someone training hard it rises to 120 g. The spread between defensible rates is more than double, which is why the rate deserves more thought than the multiplication.
Common mistakes
- Using a rate from bodybuilding sources as a general target. They are aimed at a specific population and training load.
- Assuming more is always better. Benefits plateau, and excess protein is used as energy rather than stored as muscle.
- Counting only meat and dairy. Beans, lentils, tofu, nuts, grains and vegetables all contribute.
- Ignoring distribution. Spreading intake across meals appears to matter more than the daily total for maintaining muscle.
- Using this figure if you have kidney disease. Protein intake may need restricting, and that is a clinical decision.
Frequently asked questions
Do I need protein supplements?
Most people do not. Powders are a convenient way to reach a higher intake if you are training seriously and struggling to eat enough, but they offer nothing food does not. For someone eating a varied diet at ordinary activity levels, the reference intake is usually met several times over without thinking about it.
Is plant protein as good as animal protein?
For meeting daily needs, yes, provided the diet is varied. Individual plant sources have different amino acid profiles, but eating a range across the day covers this without any need to combine foods at a single meal — the older advice about protein combining has been superseded. Vegans should pay separate attention to B12, iron and iodine rather than to protein.
Can too much protein damage the kidneys?
In people with healthy kidneys, there is no good evidence that higher protein intakes cause harm. In people with existing kidney disease, protein intake is often managed clinically and higher intakes may be inadvisable. If you have any kidney condition, take the question to your clinical team rather than a calculator.
Does protein help with weight management?
It is more satiating than carbohydrate or fat gram for gram, and adequate protein helps preserve lean mass during weight loss. That makes it useful as part of an overall approach, though it is not a mechanism for losing weight on its own.
Is what I enter stored?
No. Your weight and chosen rate are processed in your browser and never transmitted or retained. If thinking about food or eating is causing you distress, tracking intake against a target may make that harder rather than easier. Beat, the UK eating disorder charity, runs a free helpline and online support, and a GP can refer you to specialist services.
Related tools
References
- NHS — protein in the diet and healthy eating guidance
- GOV.UK — Scientific Advisory Committee on Nutrition dietary reference values for protein
Sources are checked at publication and can change — how I choose and check references.