Pick up a jar of pasta sauce from Italy, a packet of biscuits from the UK, or a bag of crisps from anywhere in the EU, and the panel on the back will look almost familiar. It lists energy, fat, carbohydrate, protein — and then, where you expect sodium in milligrams, it gives you salt in grams, measured against 100 grams of product rather than a serving.
Nothing has been hidden. Two conversions turn that panel into a number you can log.
Difference one: salt, not sodium
Sodium chloride is only about 40% sodium by weight, so the two figures differ by a factor of roughly 2.5. Salt equals sodium multiplied by 2.5. Sodium equals salt divided by 2.5. One gram of salt on a European label is about 400 mg of sodium on a US one.
| Salt on the package | Sodium equivalent |
|---|---|
| 0.3 g | 120 mg |
| 0.5 g | 200 mg |
| 1 g | 400 mg |
| 1.5 g | 600 mg |
| 2.5 g | 1,000 mg |
| 6 g | 2,400 mg — roughly the US daily upper limit |
Difference two: per 100 g, not per serving
EU rules require nutrition information per 100 g or per 100 ml; a per-portion column is optional and often absent. That is inconvenient if you want to know what one biscuit costs you, and genuinely better if you want to compare two products.
To get from per 100 g to your portion, multiply by the portion weight in grams and divide by 100. The pack weight on the front usually gives you what you need — a 40 g bag eaten whole is 0.4 of the printed figure.
A worked example
- Read the salt figureA loaf of bread lists 1.1 g of salt per 100 g.
- Scale to your portionA slice weighs about 40 g, so 1.1 × 0.4 gives roughly 0.44 g of salt per slice.
- Convert to sodium0.44 divided by 2.5 is about 0.176 g, or roughly 176 mg of sodium per slice.
- Log the portion, not the panelTwo slices in a sandwich is about 350 mg before anything goes between them.
Front-of-pack colours in the UK
Many UK products carry a voluntary colour-coded panel on the front. For salt, green means low at 0.3 g or less per 100 g, amber is the range in between, and red means high at more than 1.5 g per 100 g. A large portion can also push a product into red on its own.
The reference intake printed alongside is 6 g of salt a day for adults, about 2,400 mg of sodium. The World Health Organization recommends less than 5 g of salt, around 2,000 mg of sodium. Both sit in the same neighbourhood as the US figure of 2,300 mg, which is reassuring when you are comparing guidance across countries.
Other panels you may run into
- Canada — sodium in milligrams per serving with a %DV, measured against the same 2,300 mg reference used in the US
- Australia and New Zealand — sodium in milligrams, shown both per serving and per 100 g, so both reading styles are available
- Japan and much of Asia — often sodium in milligrams per 100 g, with salt equivalent sometimes shown alongside
The underlying arithmetic never changes: find the unit, find the denominator, then rescale to what you are eating. Scanning the panel with Sodi does the conversion for you, which mostly saves you from doing division in a supermarket aisle.
A panel in a different format is not a panel in a different language. It is the same number wearing different units.
This article is general information about nutrition labels and sodium, not medical advice. If you have been given a specific sodium target, follow the guidance of your doctor or dietitian.