A practical guide to sodium-to-salt conversion, serving-size checks and country-specific label values, with WHO guidance as the global benchmark.
Key Takeaways
- Multiply sodium in grams by 2.5 to calculate salt equivalent; 400 mg sodium is approximately 1 g salt.
- WHO recommends that adults consume less than 2,000 mg sodium, equivalent to less than 5 g salt, per day.
- Compare similar products using the same serving size or sodium per 100 g, then account for the amount you will eat.
- Daily Value percentages and claims such as “low sodium” vary by country and should not be treated as global standards.
Some food labels list sodium, while others declare salt. They are not the same measurement, but you can convert between them: multiply sodium by 2.5 to estimate its salt equivalent, or divide salt by 2.5 to estimate sodium.
Sodium-to-salt conversion
The European Union’s standardized calculation for nutrition labels is:
Salt (g) = sodium (g) × 2.5
When sodium is shown in milligrams, convert it to grams before multiplying:
Salt (g) = sodium (mg) ÷ 1,000 × 2.5
This can also be shortened to:
Salt (g) = sodium (mg) × 0.0025
- 1,000 mg sodium equals 2.5 g salt.
- 400 mg sodium equals approximately 1 g salt.
To work in the other direction:
Sodium (g) = salt (g) ÷ 2.5
In milligrams, each gram of salt is equivalent to approximately 400 mg sodium.
Why salt and sodium are not interchangeable terms
Regular table salt consists mainly of sodium and chloride, but it is not the only possible source of sodium in food. Sodium may occur naturally or come from ingredients such as monosodium glutamate, sodium bicarbonate and sodium nitrite.
For that reason, a calculated “salt” declaration can represent the salt equivalent of total sodium. It does not necessarily tell you how much sodium chloride was physically added during manufacturing. A product also does not have to taste particularly salty to contribute substantial sodium.
How much sodium does WHO recommend?
The World Health Organization recommends that adults consume less than 2,000 mg of sodium per day. Using the conversion above, that is equivalent to less than 5 g of salt per day.
For children aged 2 to 15, WHO says the adult limit should be adjusted downward according to energy requirements. Individual medical advice may set a different limit.
WHO reports that global mean adult intake in 2021 was 4,278 mg sodium per day, equivalent to about 11 g of salt. Excessive sodium intake raises blood pressure and cardiovascular risk.
The WHO recommendation is global public-health guidance. It should not be confused with the Daily Value or reference intake printed on a national food label. Those national figures and labelling rules can differ.
How to compare sodium across products
Use the same basis for both products
Start by checking whether each figure is listed per serving, per 100 g or in another quantity. A lower number does not necessarily mean a lower-sodium product if the stated quantities differ.
When labels provide it, comparing sodium per 100 g across similar foods avoids differences created by manufacturer serving sizes. This is the approach recommended by Food Standards Australia New Zealand. Compare like with like, because sodium levels across unrelated types of food do not answer the same purchasing question.
Check how much you will actually eat
A nutrition label’s serving size is the quantity used to calculate its nutrient figures. It may not match your actual portion. After comparing products on an equal basis, consider the amount you expect to consume.
Convert only when the labels use different nutrients
If one product lists sodium and another lists salt, convert both to the same unit before comparing them. If both already show sodium per 100 g, no salt conversion is needed.
Why Percent Daily Value varies by country
Percent Daily Value can help compare products within one national labelling system, but its meaning is not identical worldwide.
- United States: The Daily Value is less than 2,300 mg sodium per day. On a serving-based label, 5% Daily Value or less is considered low, while 20% or more is considered high.
- Canada: Health Canada describes 5% Daily Value or less as a little and 15% or more as a lot.
The different high thresholds are jurisdictional labelling differences, not a disagreement about the sodium-to-salt calculation. For cross-border comparisons, the sodium amount in milligrams is generally more directly comparable than the displayed percentage, provided the quantities or serving sizes are aligned.
What “low” and “reduced” sodium claims mean
Front-of-package claims also depend on local regulations. In the United States, “sodium-free” means less than 5 mg per serving, “very low sodium” means 35 mg or less, and “low sodium” means 140 mg or less. “Reduced sodium” requires at least 25% less sodium than the regular product, while “light in sodium” requires at least 50% less.
In Australia and New Zealand, a low-salt food contains no more than 120 mg sodium per 100 g. A reduced salt or sodium product must contain at least 25% less than the comparative reference food and meet other applicable sodium conditions.
These terms should therefore be interpreted under the rules of the market where the product is sold. A “reduced” claim is also relative to a comparison product; it does not by itself establish that the food is low in sodium.
What This Means
For a quick sodium-to-salt conversion, remember that 400 mg sodium is approximately 1 g salt. When choosing between packaged foods, first align the serving size or use the per-100-g figures, then compare sodium directly. Finally, account for how much you will actually eat.
WHO’s benchmark of less than 2,000 mg sodium, or less than 5 g salt, provides global context. National Daily Values and package claims serve a different labelling purpose and may use different thresholds. Because guidance and regulations may change, check the relevant official source and follow individualized advice from a qualified health professional where applicable.
Sources
- World Health Organization — Sodium reduction fact sheet
- European Union — Regulation (EU) No 1169/2011 on food information to consumers
- U.S. Food and Drug Administration — Sodium in Your Diet
- Food Standards Australia New Zealand — How much sodium is in Australian foods?
- Health Canada — Nutrition facts table
