Common Registration Assessment, Part 1
Salt limit calculations by age
Three original questions on daily salt limits by age and salt in a portion, using the NHS table.
Published 13 October 2026. Independent revision material, not GPhC questions, not for patient care.
The NHS page gives the maximum daily salt intake by age: 6 g for 11 and over (about 1 teaspoon), 5 g for 7 to 10, 3 g for 4 to 6, 2 g for 1 to 3, and under 1 g for babies under a year.
Questions combine this table with food labels. Salt on a label is given per 100 g, so the working is to scale to the portion and then compare with the limit for that age.
The method
- Find the age band and write the daily limit.
- Scale the label figure: salt per portion = salt per 100 g × portion in g ÷ 100.
- Add the salt from every food in the same day.
- Compare with the limit: subtract to find what is left, or divide for a percentage.
- Check the age band again, because 4 to 6 and 7 to 10 differ.
Three practice questions
Work each one on paper first, then open the answer. All patients and prescriptions are fictional.
Question 1
A family has two adults, a child aged 5, a child aged 9 and a child aged 2. What is the total daily maximum salt for the family in g?
Show the answer
Answer: 22 g
Working: 6 + 6 = 12 g for the adults. 3 g for age 5. 5 g for age 9. 2 g for age 2. 12 + 3 + 5 + 2 = 22 g.
Question 2
A child aged 8 eats 250 g of a food that has 0.6 g salt per 100 g. How much salt is that, what percentage of their daily limit, and how much is left?
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Answer: 1.5 g, which is 30%, with 3.5 g left
Working: 0.6 × 250 ÷ 100 = 1.5 g. The limit for age 8 is 5 g. 1.5 ÷ 5 = 30%. 5 - 1.5 = 3.5 g.
Question 3
An adult eats a 400 g ready meal with 2.1 g salt per 100 g. How much salt is that, and how far over the daily limit is it?
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Answer: 8.4 g, which is 2.4 g over the 6 g limit
Working: 2.1 × 400 ÷ 100 = 8.4 g. 8.4 - 6 = 2.4 g over. As a percentage of the limit, 8.4 ÷ 6 = 140%.
Exam approach
Scale the label to the portion first, then compare with the limit for the right age band.
Where marks are lost
- Using the label figure per 100 g as though it was for the whole portion.
- Using the wrong age band, for example the 3 g limit for an 8 year old.
- Leaving out salt from other meals in the day.
- Forgetting the limit for children under 1 is under 1 g.
Frequently asked questions
What is the adult limit in the NHS advice?
The NHS page says adults should have no more than 6 g of salt a day, around 1 level teaspoon, including salt in food and added during and after cooking.
Can medicines add salt?
The NHS page says some dissolvable tablets, such as painkillers, vitamins or prescription medicines, may be high in salt, and to speak to a GP before changing any medicines.
Sources
- NHS, salt in your diet
- GPhC, Common Registration Assessment specification and permitted items for 2026
The questions above are original and use fictional patients and prescriptions. PreRegExamPrep is not affiliated with or endorsed by the General Pharmaceutical Council.
Practise until the method is automatic
Try 15 free questions with worked answers. No sign-up required.
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