Protein Calculator UK NHS
This independent UK protein calculator estimates the Reference Nutrient Intake (RNI) for a healthy adult from body weight. The current UK adult reference is 0.75 g of protein per kilogram of body weight per day.
Calculate your adult protein reference
How the protein calculator works
For adults aged 19 years and over, the UK Dietary Reference Values set the protein RNI at 0.75 g/kg body weight/day. Formula: protein RNI = body weight in kg × 0.75.
Worked example
For a 70 kg adult: 70 × 0.75 = 52.5 g of protein per day.
What does RNI mean?
The Reference Nutrient Intake is a population reference intended to meet the needs of nearly all people in a group. It is not a personalised prescription or a bodybuilding target. UK guidance expresses protein requirements relative to body weight.
When protein needs may be different
Pregnancy, breastfeeding, childhood, illness, wounds, recovery from surgery, frailty and some high levels of physical activity can change protein needs. People with kidney disease or another condition affecting dietary protein should follow advice from their clinician or dietitian rather than increasing protein based on an online calculator.
Protein foods
A balanced diet can provide protein from beans, pulses, fish, eggs, meat, dairy foods and plant-based alternatives. Most healthy adults do not need specialist high-protein products simply to meet the basic UK reference intake.
Limitations
This calculator is for healthy adults and uses the general UK RNI only. It does not calculate therapeutic nutrition, sports-performance targets, paediatric requirements or an individual clinical prescription.
Authoritative sources
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FAQs
How much protein does a healthy UK adult need?
The UK adult RNI is 0.75 g per kg of body weight per day.
How much protein does a 70 kg adult need using the UK RNI?
About 52.5 g per day using 70 × 0.75.
Is this an NHS prescription?
No. It is an independent calculator using the UK general adult dietary reference value.
Should I use this if I have kidney disease?
Do not use a general calculator to change a medically prescribed diet. Ask your clinician or dietitian for individual advice.
Disclaimer: General educational information only. It is not medical or dietetic advice.