How to convert sodium to salt (and salt to sodium)

Written by Catherine Saxelby on Friday, 06 August 2010. Posted in Measures and conversions
Tagged: conversions, food labels, salt, sodium

How to convert sodium to salt (and salt to sodium)

Nutritionists suggest we cut back on salt but it's sodium you'll see listed on food labels and on any recommended daily intakes. So what's the difference and how can you convert sodium into salt? And vice versa?

 

Two ways to convert

Use our quick converter table or the handy rules.

1. Quick sodium and salt converter table

Salt in
grams 
Sodium in mg This is roughly equivalent to  
1 400 Good pinch of salt  
1.25 500 One-quarter of a teaspoon salt  
2.3 920 One-third of a teaspoon salt Lower limit of the RDI
2.5 1000 Half a teaspoon salt  
4 1600 ¾ of a teaspoon salt  
5 2000 One teaspoon salt Aim for this as your maximum day's intake
6 2400 1¼ teaspoons salt Upper limit of the RDI
10 4000 2 teaspoons salt  
12 4800 2½ teaspoons salt Average intake upper end

So 5 grams of salt is equal to 2000mg of sodium, both of which are contained in one teaspoon of salt.
If a recipe calls for one teaspoon of salt and serves 4 people, you're getting one-quarter of a teaspoon of salt from it or around 500mg sodium.

 

2. Rules

To convert the sodium to salt or salt to sodium, use these rules:

Sodium to salt

To convert sodium to salt, multiply the sodium figure in milligrams (mg) by 2.5 and then divide by 1,000. So:
millgrams of sodium X 2.5 = milligrams of salt ÷ 1,000

Example
200mg of sodium
200mg x 2.5 = 500mg salt ...  then divided by 1,000 = 0.5 grams salt
So 200mg of sodium equates to 500milligrams or 0.5 grams of salt

 

Salt to sodium

To convert grams of salt to milligrams of sodium, divide the salt figure in grams by 2.5 and then multiply by 1,000 to get milligrams. So
grams of salt ÷ 2.5 = grams of sodium X 1,000

Example
6 grams of salt
6g ÷ 2.5 = 2.4g salt ... then multiplied by 1,000 = 2400 mg of sodium
So 6 g of salt equates to 2400 milligrams of sodium

 

sodium_chloride_moleculeA little chemistry

Chemically salt is sodium chloride which is made up of one molecule of sodium plus one molecule of chloride. While half the salt molecule is sodium, it's not half by weight. So you can't just halve the weight of salt to find your sodium intake. Sodium is roughly 40 per cent of the weight of salt, with chloride the remaining 60 per cent.

In tiny quantities, both sodium and chloride are essential for health and growth. The problem today is we eat way too much sodium. For more background and tips to reduce your salt intake, click here.

 

How much sodium is too much?

Our sodium intake should be less than 2300mg per day, roughly a teaspoon (or 6 grams) of salt. Ideally, getting your sodium to less than 1600mg per day is even better as it can help prevent ill health later in life. We suggest you use the mid-point figure of 2000mg sodium as a convenient figure to remember.

But the average daily intake is somewhere between 6 to 12 grams of salt (or 6000 to 12 000 milligrams) which roughly equates to 2 300 to 4 600 milligrams of sodium. So we're consuming double the amount we need.

 

Sodium - what's low?

Low_Sodium_V8_label_close_upLess than 120mg sodium per 100grams.

See the figure of 110mg per 100g in the right hand column of a food label of a low-salt food.

Low-salt foods are unsalted foods such as unsalted butter, canned bakedn beans or canned tomatoes with no added salt and fresh produce like vegetables, fruits, nuts, milk, fish, meat, eggs, oils, rice and other unprocessed grains.

Heinz baked beans sodium 

Sodium - what's high?

More than 600mg sodium per 100grams
But this can vary from food category to category eg for bread, any bread under 400mg is considered acceptable; for salty sauces, anything under 1000mg is a good achievement.

 

Other forms of sodium apart from salt

A food may contain NO salt (sodium chloride) but may still be high in sodium because of the presence of naturally-occurring sodium (as in celery or spinach) or other sodium containing ingredients and additives such as:

baking powder/baking soda     sodium bicarbonate

flavour enhancer

monosodium glutamate (MSG)
preservatives                                           sodium benzoate, sodium nitrite, sodium sulphite
antioxidant sodium ascorbate (the sodium salt of ascorbic acidor Vitamin C). You'll see this as an additive in many white wines under the additive code no 300

 

Compare high, medium and lower salt foods

Look at these three categories of compare a similar category food in the high, medium and low category eg corn flakes (highest in salt) vs weet-bix (medium) vs oats (lower).

Food Serve Mg sodium per serve g salt per serve
High      
Kellogg's corn flakes 1 cup, 30g 204 0.5
Croissant 1, 57 g 424 1.1
Kraft Premium crackers, original 4 biscuits, 29 g 234 0.6
Lemnos feta cheese 3 cubes, 30 g 310 0.8
John West anchovies 6 fillets, 27 g 2,130 5.3
Primo bacon 2 rashers, 50g 600 1.5
Stock (eg Campbell's chicken) 1 cup, 250 ml 1,118 2.8
Soy sauce 1 tablespoon, 20 ml 1,500 3.8
       
Medium      
Sanitarium Weetbix 2 biscuits, 30 g 87 0.2
Golden crumpet 1, 50 g 300 0.8
Arnotts Vita weat 4 crackers, 23 g 105 0.3
Bega tasty cheese 1 slice, 25 g 153 0.4
Greenseas tuna in brine 1/3 cup, 65 g 310 0.8
Primo shaved chicken breast 1 serve, 50 g 424 1.1
Continental Chicken noodle soup 1 packet, made to 250 ml 765 1.9
Masterfoods tomato sauce 1 tablespoon, 20 ml 148 0.4
       
‘Lower' *      
Uncle Toby's rolled oats 1 serve, 40 g uncooked 5 Less than 0.1
Sunblest, white bread 1 slice, 30 g 120 0.3
Pureharvest rice cakes 2 crackers, 22 g 32 0.1
Mainland Mozzarella cheese 1 slice, 25 g 138 0.4
Farmer's Best regular milk 1 glass, 250 ml 110 0.3
Fresh fish, cooked, no salt 1 serve, 100 g 100 0.3
Fresh red meat, cooked, no salt 1 small steak, 100 g 45 0.1
Home-made chicken stock, no salt 250 ml 230 0.6
Baxter's mango chutney 1 tablespoon, 20 g 84 Less than 0.1
       
Suggested daily maximum   2000 5

Figures taken from food labels as at 2011

* We have classed these items as "low" compared to other products. However, some of these do not meet the official government definition of less than 120 mg per 100g.
However they are all under 400mg per 100g.

Downloads / Fact Sheets

Download our free Fact Sheet Cut down on salt

Catherine Saxelby

About the Author

Catherine Saxelby knows nutrition! She is an accredited nutritionist, food commentator, blogger and award-winning author. Her latest book - Catherine Saxelby's Food and Nutrition Companion – answers all those tricky questions on healthy eating, diets and supplements. It draws together a lifetime of advice and gives you all you need to know to eat right!

Comments (3)

  • abid mujtaba (male)

    abid mujtaba (male)

    05 November 2013 at 22:38 |
    In the your paragraph titled "A Little Chemistry" you say,
    "Chemically salt is sodium chloride which is made up of one molecule of sodium plus one molecule of chloride." which is not quite correct scientifically speaking. It would be better to say, "Chemically salt is sodium chloride (NaCl) and one molecule of sodium chloride is made up of one atom of sodium (Na) plus one atom of chlorine (Cl)."
  • Ed

    Ed

    31 December 2013 at 07:12 |
    I want to add salt to 1lb of unsalted butter how much salt should I add to get 90mg 4%
    • Catherine Saxelby

      Catherine Saxelby

      03 January 2014 at 12:55 |
      Hi Ed. Not sure what you mean by 90mg and 4%. Do you mean you want to reach a salt level of 90mg per 100 grams? 4% salt for butter is way over what's usual which is 2% added salt or around 800mg of sodium. So I'll assume you mean 90mg sodium per 100 grams. Unsalted butter has very little sodium ie less than 50mg. So 90 mg is roughly equivalent to 0.5% added salt OR 0.5g per 100 grams. Multiply this by 5 to get 500 grams or 1lb, then you need to 2.5grams of added salt. This is approx half a level teaspoon of salt which you'd need to whip into the softened butter. Does this answer your query? Catherine

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