Hong Life CalculatorsUnderstanding the sodium to salt converter — concept and principle
Food labels in many countries list sodium in milligrams, while health advice and recipes often talk about grams of salt. This converter turns sodium into the equivalent amount of table salt (sodium chloride) and shows the result as a percentage of the World Health Organization's daily sodium limit.
How it is calculated
- Salt (g) = sodium (mg) × 2.542 ÷ 1,000
- Share of WHO limit (%) = sodium (mg) ÷ 2,000 × 100
Enter sodium in milligrams. The division by 1,000 converts milligrams to grams. To go the other way, sodium (mg) = salt (g) × 1,000 ÷ 2.542, or roughly salt × 393.
The principle
Table salt is sodium chloride, NaCl. One sodium atom weighs about 22.99 atomic mass units and one chlorine atom about 35.45, so a formula unit weighs 58.44. Sodium therefore makes up 22.99 ÷ 58.44 ≈ 39.3% of salt by weight, and the salt weight is 58.44 ÷ 22.99 ≈ 2.54 times the sodium weight. The conversion assumes that all the sodium comes from sodium chloride. In processed foods some sodium comes from other additives such as sodium bicarbonate or monosodium glutamate, so the "salt equivalent" is a convenient comparison figure rather than the actual weight of salt added.
Worked example
- Default input: 2,000 mg sodium.
- Salt = 2,000 × 2.542 ÷ 1,000 = 5.084 g, shown as 5.08 g.
- Share of WHO limit = 2,000 ÷ 2,000 × 100 = 100%.
The calculator shows 5.08 g of salt and 100% of the WHO limit.
| Sodium (mg) | Salt (g) |
|---|---|
| 500 | 1.27 |
| 1,000 | 2.54 |
| 1,500 | 3.81 |
| 2,000 | 5.08 |
| 2,500 | 6.35 |
| 3,000 | 7.63 |
| 4,000 | 10.17 |
How to read the result
The WHO recommends less than 2,000 mg sodium a day for adults, which is just over 5 g of salt, about one level teaspoon. Average intakes in many countries are well above this, often 3,500–4,500 mg of sodium. Anything above 100% means the day's total already exceeds the guideline. When reading a label, multiply the sodium per serving by the number of servings you actually eat; a single bowl of noodle soup or a fast-food meal can supply more than half of the daily limit on its own.
Common mistakes
- Treating sodium and salt as the same number, which understates salt by a factor of about 2.5.
- Forgetting the unit: labels may give sodium in mg and salt in g.
- Converting only one product and forgetting sauces, soups, bread and pickles across the day.
Frequently asked questions
How much salt is in a teaspoon?
A level teaspoon of fine table salt weighs roughly 5–6 g, which contains about 2,000–2,300 mg of sodium.
Is sea salt or pink salt lower in sodium?
Not meaningfully. By weight they are still mostly sodium chloride; larger crystals only mean less salt fits in a spoon.
Why do UK and EU labels show salt instead of sodium?
EU labelling rules require the salt equivalent, calculated as sodium × 2.5, because consumers find grams of salt easier to relate to.
Sources: World Health Organization. Guideline: Sodium intake for adults and children. Geneva: WHO, 2012. · Regulation (EU) No 1169/2011 on the provision of food information to consumers, Annex I.