Sodium and salt are not the same thing
Sodium is a chemical element and an essential electrolyte the body needs for fluid balance and nerve and muscle function. Salt, more precisely sodium chloride (NaCl), is a compound made of sodium and chloride, and is the primary dietary source of sodium in most diets. Nutrition labels in different countries report one or the other — some list "sodium" in milligrams, others list "salt" in grams — which is a common source of confusion when comparing products or guidelines.
Because sodium makes up only part of salt's total mass (chloride accounts for the rest), a given weight of salt contains less sodium by weight than the salt figure itself. Converting correctly between the two requires a specific conversion factor rather than treating milligrams of sodium and grams of salt as interchangeable on a like-for-like basis.
The 2.5x conversion: sodium to salt
Sodium content is converted to its salt (sodium chloride) equivalent by multiplying by approximately 2.5, reflecting the ratio between the molecular weight of sodium chloride and the atomic weight of sodium alone. This is the same conversion factor used by public-health bodies and food-labelling guidance when translating sodium figures into everyday salt amounts, including guidance from the UK Food Standards Agency and Public Health England.
Applying the formula, salt equivalent (g) = total sodium (mg) × 2.5 ÷ 1,000. For example, 2,000 mg of sodium is equivalent to 2,000 × 2.5 ÷ 1,000 = 5 g of salt, and 1,500 mg of sodium is equivalent to 1,500 × 2.5 ÷ 1,000 = 3.75 g of salt. This is why the WHO's 2,000 mg/day sodium limit is commonly restated as "less than about 5 g of salt per day."
WHO and AHA sodium limits
The World Health Organization's guideline on sodium intake recommends adults consume less than 2,000 mg of sodium per day, equivalent to less than about 5 g of salt, as a population-level target for reducing cardiovascular disease risk. The American Heart Association sets a more conservative "ideal limit" of no more than 1,500 mg of sodium per day for most adults, particularly those managing blood pressure, while also citing a general upper limit of 2,300 mg/day in its broader guidance materials.
These figures are not identical to one another, and it is worth being precise about which one a given comparison is using: the WHO's 2,000 mg figure, the AHA's more conservative 1,500 mg ideal limit, and the AHA's separate 2,300 mg general upper limit are three distinct reference points from two different organizations, not three versions of the same number.
Where dietary sodium hides
In many countries, the largest share of dietary sodium comes from processed, packaged and restaurant foods rather than salt added during home cooking or at the table. Common contributors include bread and baked goods, cured and processed meats, cheese, canned soups, and prepared sauces and condiments — categories that are not always perceived as "salty" by taste alone.
This is a practical, frequently underestimated point: many high-sodium foods, including bread and breakfast cereals, do not taste distinctly salty, which means checking nutrition labels is a more reliable way to track sodium intake than relying on taste.
Potassium's role: a qualitative counterbalance
Potassium is another essential electrolyte, and the World Health Organization has separately published dietary guidance on potassium intake, recommending increased consumption of potassium-rich foods as part of a broader strategy for supporting healthy blood pressure. Potassium and sodium interact in the body's regulation of blood pressure and fluid balance, and increasing potassium intake through foods such as fruits, vegetables and legumes is one dietary approach discussed alongside sodium reduction in public health guidance, rather than a substitute for it.
This relationship is discussed here in general, qualitative terms rather than with a specific numeric target, because individual potassium needs and appropriateness can vary — for example, people with kidney disease or those taking certain medications may need to limit rather than increase potassium intake, which is a reason to discuss any significant dietary change with a healthcare professional or registered dietitian rather than adjusting potassium intake based on general population guidance alone.
Câu hỏi thường gặp
What is the difference between sodium and salt?
Sodium is a chemical element and essential electrolyte; salt (sodium chloride) is a compound made of sodium and chloride, and is the main dietary source of sodium. Some nutrition labels report sodium in milligrams and others report salt in grams, so converting between the two requires a specific conversion factor rather than treating the figures as interchangeable.
How do you convert sodium to salt?
Multiply the sodium value in milligrams by approximately 2.5 and divide by 1,000 to get grams of salt. This factor reflects the ratio between the molecular weight of sodium chloride (salt) and the atomic weight of sodium alone. For example, 2,000 mg of sodium equals 2,000 × 2.5 ÷ 1,000 = 5 g of salt.
How much sodium should I eat per day?
The World Health Organization recommends adults consume less than 2,000 mg of sodium per day, equivalent to less than about 5 g of salt. The American Heart Association sets a more conservative ideal limit of no more than 1,500 mg/day for most adults, alongside a separate general upper limit of 2,300 mg/day cited in its broader materials.
What foods are highest in sodium?
In many countries, the largest share of dietary sodium comes from processed, packaged and restaurant foods — such as bread, cured meats, cheese, canned soups and sauces — rather than salt added during home cooking or at the table. Checking nutrition labels is a more reliable way to track sodium than judging by taste, since many high-sodium foods do not taste distinctly salty.
Does potassium counteract the effects of sodium?
Potassium and sodium interact in the body's regulation of blood pressure and fluid balance, and the World Health Organization has published separate dietary guidance recommending increased intake of potassium-rich foods such as fruits, vegetables and legumes as part of broader blood-pressure-related dietary guidance. This is a general, population-level dietary pattern rather than a way to directly offset a specific sodium intake, and individual potassium needs vary — some people, including those with kidney disease, may need to limit rather than increase potassium, which is worth discussing with a healthcare professional.
Tài liệu tham khảo
- World Health Organization. Guideline: Sodium intake for adults and children. WHO, Geneva, 2012.
- World Health Organization. Guideline: Potassium intake for adults and children. WHO, Geneva, 2012.
- World Health Organization. Salt reduction fact sheet. who.int.
- American Heart Association. How much sodium should I eat per day? heart.org.
- UK Food Standards Agency / Public Health England. Guidance on the sodium-to-salt conversion factor used in nutrition labelling.