Salt and sodium are not the same quantity, and the gap between them is large enough to change every number on a nutrition panel. Table salt is sodium chloride: roughly two fifths of its weight is sodium and the rest is chloride. So a food listing 1 gram of salt contains about 400 milligrams of sodium, and a food listing 400 milligrams of sodium contains about 1 gram of salt. This salt to sodium converter moves between the two in either direction, and between grams, milligrams, teaspoons and millimoles, so you can put a European label, an American label, a recipe and a lab report on one scale.
Arb Digital publishes this as a unit converter and nothing more. It does the arithmetic and cites the factor it uses. It does not tell you how much sodium to eat, because that is a question about an individual person and their health, and no web page has the information needed to answer it. Where the tool shows published limits, it shows them as what a named organisation has published, with a link, and leaves the interpretation where it belongs.
What This Salt to Sodium Converter Does
It takes one amount in one of six units and expresses it in all of them. Enter 6 grams of salt and it returns the sodium content in milligrams, grams and millimoles, plus the teaspoon equivalent. Enter 2,300 milligrams of sodium and it runs the same conversion backwards to give you salt in grams and teaspoons. A servings field divides a whole-recipe or whole-pack quantity down to a single portion, which is the step most people do wrong when reading a label that quotes per-pack rather than per-serving figures.
It also lets you choose the conversion basis. The molar-mass basis is exact chemistry. The rounded convention used in public-health communication treats 1 gram of salt as 400 milligrams of sodium. The two answers differ by less than two percent, but the tool exposes the choice rather than hiding it, because a converter that will not show its own assumption is not much use.
Sodium in cooking is a different problem from sodium in a swimming pool, and our pool salt calculator handles that one — it works out how much salt to add to reach a target parts-per-million concentration in pool water, which is a dilution problem rather than a unit conversion. If you are salting a brine for meat, the brine calculator owns that job: brine strength is a percentage of the water weight, not a per-serving sodium figure.
How to Use It
- Enter the amount and pick its unit. Read the label carefully first. European and UK panels usually state salt; United States panels state sodium. Getting this one selector right matters more than anything else on the page.
- Choose the conversion basis. Molar masses for chemistry and precision work, the rounded convention if you want your figure to match published guidance material exactly.
- Set the teaspoon weight if you know it. The default of 6 grams suits fine table salt. Kosher and flaky salts can be half that per spoon, which changes the teaspoon output dramatically and nothing else.
- Set servings if you started from a whole pack or a whole recipe. The tool divides every output by this number, so the grid always reads per serving.
- Read the grid, then the bars. The grid is the conversion. The bars are a comparison with two published limits, shown with their sources named.
The Conversion Factor and How It's Calculated
Sodium chloride has a molar mass of about 58.44 grams per mole, made up of sodium at 22.99 and chlorine at 35.45. Sodium therefore accounts for 22.99 divided by 58.44, which is 0.3934, or 39.34 percent of the weight of pure salt. Turning that around, salt weighs 58.44 divided by 22.99 times as much as the sodium inside it, which is 2.542. Those two numbers are the whole conversion:
sodium (mg) = salt (g) × 393.4 and salt (g) = sodium (mg) ÷ 393.4, or equivalently salt = sodium × 2.542 when both are in the same unit.
The World Health Organization's published guidance rounds this, stating that 1 gram of salt is equivalent to 400 milligrams of sodium and that 5 grams of salt is equivalent to 2,000 milligrams of sodium in its Sodium reduction fact sheet. That is the factor of 2.5 you will see quoted almost everywhere. Millimoles come from the same molar mass: 1 millimole of sodium weighs 22.99 milligrams, so sodium in mmol is sodium in milligrams divided by 22.99. Clinical laboratories and some renal and cardiology material use mmol, which is why the unit is here at all.
Work the default through. Six grams of salt, on the molar basis, is 6 × 393.4 = 2,360 milligrams of sodium. That is 2.36 grams of sodium, or 2,360 ÷ 22.99 = 102.7 millimoles. At 6 grams per level teaspoon it is exactly one teaspoon. Switch the basis to the WHO convention and the same 6 grams gives 6 × 400 = 2,400 milligrams — forty milligrams apart, which is the entire practical difference between the two methods at this scale.
Why Labels Disagree Across Borders
The reason this converter exists is that two large labelling traditions chose different quantities. United States nutrition panels declare sodium in milligrams. United Kingdom and European Union panels declare salt in grams. Both are describing the same substance in the food; they simply pick a different half of it to print. A tinned soup showing 0.9 g salt in London and the identical recipe showing 354 mg sodium in Chicago are the same product.
This produces a specific and very repeatable mistake. Someone comparing a British packet at 1.2 g with an American packet at 480 mg concludes that the British one has more than twice the sodium. In fact 1.2 g of salt is 472 mg of sodium, so the two products are within two percent of each other. The factor of 2.5 sitting silently between the two systems is enough to reverse a comparison entirely.
There is a second, quieter trap in the serving size. Panels declare per 100 g, per serving, or per pack, and the basis is often printed in smaller type than the number. A figure that looks alarming per 100 g can be modest per portion, and a figure that looks modest per serving can be substantial if the pack holds three servings and gets eaten in one sitting. The servings field on this page exists for exactly that adjustment, and it is the same discipline our meal calorie calculator applies to energy figures.
Teaspoons Are the Least Reliable Unit Here
A teaspoon is a volume, and salt is sold in wildly different crystal sizes, so the weight of a teaspoon of salt is not a constant. Fine table salt packs densely and lands somewhere near 6 grams per level teaspoon; the NHS uses 6 g as roughly one level teaspoon. The WHO fact sheet describes 5 g as approximately one teaspoon. Both are right for the salt each was describing.
Coarse kosher salt, flaked sea salt and flor de sal all trap air between large crystals and can weigh 3 to 4 grams per teaspoon, sometimes less. That is a difference of nearly two to one, which means substituting one salt for another spoon-for-spoon in a recipe changes the sodium content of the dish substantially even though the measuring spoon never changed. This is why serious baking and charcuterie recipes specify salt by weight, and why our baker's percentage calculator and sourdough hydration calculator both work in grams throughout.
The teaspoon field on this page is editable for that reason. If you weigh a level teaspoon of the salt in your own kitchen once, on a scale that reads to a tenth of a gram, you will have a figure that is right for your salt rather than an average of everyone's.
Sodium That Never Came From a Salt Cellar
Converting salt to sodium tells you about sodium chloride. It does not capture every sodium compound in a food, and in processed products it often misses a lot. Sodium bicarbonate in baking, sodium benzoate and sodium nitrite as preservatives, monosodium glutamate as a flavour enhancer, and various sodium phosphates in cured and processed meats all contribute sodium without contributing salt.
The practical consequence is directional and worth knowing: converting a declared sodium figure into salt is always safe, because you are simply restating the number the manufacturer measured. Converting a recipe's added salt into a total sodium figure is not, because it silently assumes salt is the only source. A loaf of bread with baking soda, or a bacon cure using nitrite, will contain more sodium than its added salt implies. If you need a total, use the declared sodium figure from the label as your starting point and let this tool run in the salt direction.
The same reasoning applies to salt substitutes. Potassium chloride replaces some or all of the sodium chloride, so a substitute product converts on a different basis entirely and this page's factor does not describe it. Read the panel on the specific product rather than assuming.
What the Published Limits Say, and Who They Are For
Two figures appear on the bars. The World Health Organization recommends adults consume less than 2,000 mg of sodium per day, equivalent to less than 5 g of salt, in the fact sheet linked above. The NHS advises that adults in the UK should eat no more than 6 g of salt a day, around one level teaspoon, on its Salt in your diet page. Those two are not in conflict; they are separate bodies issuing separate population-level recommendations, and the numbers land close together.
What matters is what kind of statement they are. Both are population guidance aimed at national averages, and both bodies say children's figures should be lower and scaled to age. Neither is a personal prescription, and neither takes account of medication, kidney function, heart failure, pregnancy, heavy sweating, athletic training or any of the many circumstances that legitimately move an individual figure in either direction. Some people are advised by their clinicians to take in more sodium, not less. This page has no way of knowing which situation applies to you, so it shows the published numbers, names who published them, and stops there.
If you are tracking intake alongside other nutrition figures, our net carbs calculator and glycemic load calculator take the same approach: published formulas, named sources, no targets.
Arb Digital builds calculators that cite their constants, expose their assumptions and stay inside their remit — the same standard as this page.
Browse All Free Tools Talk To Our TeamCommon Mistakes to Avoid
- Treating salt and sodium as interchangeable words — they differ by a factor of about 2.5, which is enough to make a low-sodium food look high or the reverse.
- Comparing a per-100 g figure with a per-serving figure — the basis is printed in small type and is where most label comparisons go wrong.
- Assuming a teaspoon is a fixed weight — fine table salt and flaked sea salt can differ by nearly two to one per spoon.
- Converting added salt to a total sodium figure — baking soda, nitrites, MSG and phosphates all add sodium that no salt conversion will show.
- Reading a population limit as a personal target — the published figures describe populations, and an individual figure is a clinical question.
Related Free Tools From Arb Digital
Work out brine strength by weight with the brine calculator, convert a recipe to flour-relative ratios with the baker's percentage calculator, handle starter flour and water with the sourdough hydration calculator, read carbohydrate figures with the net carbs calculator and the glycemic load calculator, or size a holiday menu with the Thanksgiving dinner calculator. The free online tools hub lists everything we publish.
Frequently Asked Questions
Multiply grams of salt by 393.4 to get milligrams of sodium, or divide grams of salt by 2.542. Using the rounded convention, 1 gram of salt is 400 milligrams of sodium, so multiplying by 400 gives a figure within two percent.
Multiply the sodium figure by 2.542 to get the equivalent weight of salt, or divide milligrams of sodium by 393.4 to get grams of salt. Both directions use the same molar ratio.
Because sodium is only part of the salt molecule. Sodium chloride has a molar mass of 58.44 and sodium accounts for 22.99 of that, so sodium is 39.34 percent of the weight and salt is 2.542 times heavier than the sodium it contains.
Published figures for fine table salt sit between 5 and 6 grams per level teaspoon. Coarse kosher and flaked sea salts can weigh 3 to 4 grams per teaspoon because the larger crystals trap air, so weighing your own salt once is more reliable than any average.
A millimole is a quantity of molecules rather than a weight. One millimole of sodium weighs 22.99 milligrams, so dividing milligrams of sodium by 22.99 converts to mmol. Clinical laboratories often report sodium in this unit.
No. It tells you the sodium contributed by sodium chloride. Baking soda, sodium nitrite, monosodium glutamate and sodium phosphates all add sodium without adding salt, so a declared sodium figure on the label is the more complete number.
The World Health Organization recommends adults consume less than 2,000 mg of sodium per day, equivalent to less than 5 g of salt. The NHS advises adults eat no more than 6 g of salt a day. Both are population-level recommendations rather than individual targets.
No. This is a unit converter. An appropriate individual intake depends on health conditions, medication and circumstances that this page knows nothing about, and only a clinician or registered dietitian can advise on it.
This page is a unit converter provided for general information. It is not medical or dietary advice, it does not set an intake target for anyone, and it is not a substitute for guidance from a qualified clinician or registered dietitian, who is the only appropriate source for an individual sodium recommendation.
