Sodium & Salt Intake Calculator

Salt Intake Guide

What should I know about UK Salt Limits?

NHS salt intake recommendations: adults: maximum 6g salt/day (= 2.4g sodium). Children 11+: 6g. 7-10 years: 5g. 4-6 years: 3g. 1-3 years: 2g. Under 1: less than 1g (food should not be salted at all). Sodium vs salt: 1g sodium = 2.5g salt. Most labels show sodium per portion. Multiply by 2.5 to get salt equivalent. UK average intake: 8.4g salt/day (40% above recommended limit). Has fallen from 9.5g in 2003 due to gradual food industry reformulation, but still too high. People with high blood pressure or existing cardiovascular disease benefit most from reducing intake toward or below the recommended limit, since they're most sensitive to salt's blood-pressure-raising effect.

What's the key thing to understand about Hidden Salt Sources?

Major UK sources of dietary salt (Public Health England data): bread: 23% (3 slices/day at 0.4g per slice = 1.2g). Processed meat (bacon, sausages, ham): 13%. Cheese: 10%. Ready meals and takeaway: 10%. Pasta sauces and condiments: 8%. Soups: 5%. Snack foods (crisps, salted nuts): 5%. Surprisingly: only 15-20% of salt intake comes from salt added in cooking or at the table. Most comes from processed and pre-packaged foods where consumers cannot control it. Check labels: 'high' means over 1.5g of salt per 100g of the food, a useful quick reference when comparing similar products in the supermarket.

What should I know about Health Impact of Excess Salt?

High salt intake causes: high blood pressure (hypertension). 1 in 3 UK adults affected. Increases risk of stroke, heart attack, kidney disease, heart failure. Stomach cancer — strong link with high-salt diets. Osteoporosis — high salt increases calcium excretion. Kidney stones. Reducing salt: each 1g/day reduction lowers BP by approximately 1mmHg (less effect in those without hypertension). Population studies: 3g/day reduction would prevent ~20,000 UK CVD deaths annually. Effective interventions at a population level — reformulating processed food to contain less salt — have historically achieved far more than individual dietary advice alone.

What's the key thing to understand about Reducing Salt Practically?

Easy substitutions: choose 'reduced salt' bread or rotate brands. Some bread can have 50% less salt than others. Make your own salad dressings (control salt levels) rather than shop-bought. Cook from scratch where possible. Even basic home cooking has dramatically less salt than ready meals. Read labels — different brands of the same product can vary 2-3× in salt. Limit processed meats: bacon to 1-2 portions/week. Sausages: high-quality with lower salt. Limit cheese: keep portions to 30g. Choose reduced-salt versions of common condiments and stock cubes, since these are often surprisingly high in sodium relative to how much is actually used per serving.

What should I know about Sodium and Blood Pressure — The Evidence?

The link between salt intake and blood pressure is one of the most consistently replicated findings in nutrition science. Excess sodium causes the body to retain more fluid, which increases blood volume and the pressure on artery walls; over years, this contributes to sustained high blood pressure (hypertension), a major risk factor for stroke and heart disease. Population studies comparing countries and the long-running DASH-Sodium trial, among others, consistently show that reducing salt intake lowers blood pressure, with the effect larger in people who already have high blood pressure or who are 'salt-sensitive' — a trait that varies between individuals and is more common with age, in some ethnic groups, and with conditions like diabetes or kidney disease. This is why NHS and NICE guidance recommends a population-wide salt reduction target of no more than 6g per day for adults, rather than only advising it for people already diagnosed with hypertension: lowering average salt intake across the population measurably reduces rates of stroke and cardiovascular disease, even among people whose blood pressure is currently normal.

What should I know about Reading Food Labels for Salt?

UK front-of-pack labelling uses a traffic-light system for salt per 100g: red/high is more than 1.5g salt per 100g, amber/medium is between 0.3g and 1.5g, and green/low is 0.3g or less — checking this figure, rather than the "per portion" figure alone, makes it possible to compare similar products fairly regardless of pack size. Many foods that don't taste obviously salty are significant sodium sources, including bread, breakfast cereals, sauces and ready meals, because salt is also used as a preservative and flavour enhancer in processing, not only for taste. The ingredients list is useful too: salt, sodium, or sodium compounds such as sodium bicarbonate appearing near the top of the list signal a higher-salt product. For anyone managing blood pressure, comparing the red/amber/green colour coding across similar products — such as different brands of soup or bread — is one of the simplest practical steps recommended for reducing salt intake without needing to calculate exact grams at every meal.

What should I know about Sodium and Kidney Health?

Sodium and kidney function are closely linked: the kidneys normally regulate sodium balance, but consistently high intake makes this harder to manage and is associated with increased risk of kidney stones and, over time, with faster decline in kidney function, particularly in people who already have reduced kidney function or conditions like chronic kidney disease (CKD). For people with CKD, sodium restriction is often a more individualised and stricter target than the general population's 6g/day UK guideline, set by a renal dietitian based on blood tests and stage of disease. Conversely, some conditions and medications (such as certain diuretics, or rare kidney conditions causing sodium wasting) can make sodium restriction inappropriate or even harmful, which is why anyone with a diagnosed kidney condition should get a personalised sodium target from their care team rather than relying on general population guidance like this calculator's defaults.

Worked Example: Converting Sodium (mg) to Salt (g) on a Label

Food labels in the UK show sodium in milligrams, but the 6g/day salt recommendation is usually what people remember. The two are related by a fixed conversion: salt (g) = sodium (mg) × 2.5 ÷ 1,000, because salt (sodium chloride) is about 40% sodium by weight. Worked example: a ready meal lists 920mg of sodium per portion. Salt equivalent = 920 × 2.5 ÷ 1,000 = 2.3g of salt — just under half the recommended daily 6g salt limit (equivalent to 2,400mg sodium) in a single meal.

The 2.5 multiplier is worth memorising, since it lets you convert any sodium figure on a label into the same 6g/day salt budget most UK health guidance is framed around, without needing a calculator every time you check a label in the supermarket.

Sodium Needs for Specific Groups

The general UK adult limit this calculator works from, no more than 6g of salt (about 2.4g of sodium) a day, is a population-wide maximum rather than a target everyone should aim to hit exactly, and some groups need tailored advice. The World Health Organization sets a slightly stricter global target of under 5g of salt (about 2g of sodium) a day for adults, aimed at reducing population-wide cardiovascular risk. Children need considerably less than adults because of their smaller body size: UK guidance suggests roughly 2g of salt a day for children aged 1 to 3, rising in stages through childhood to the adult 6g limit by adolescence. People who have been specifically advised by a doctor to follow a lower-sodium diet, for example for certain kidney or heart conditions, should follow that individual clinical advice rather than the general population limit, since their appropriate target may be considerably lower.

The Sodium-Potassium Balance: Why Some Diets Also Raise Potassium

Public health advice on blood pressure increasingly looks at sodium alongside potassium, rather than sodium in isolation. Potassium helps the body excrete excess sodium and relaxes blood vessel walls, and diets that are naturally higher in potassium, built around vegetables, fruit, beans, and lower-fat dairy, such as the DASH (Dietary Approaches to Stop Hypertension) eating pattern, have consistently been shown to lower blood pressure, partly independent of sodium reduction alone. This is one reason dietary advice for blood pressure rarely stops at 'eat less salt': simply cutting processed and salty foods while also increasing vegetables and fruit tends to produce a better result than either change alone. People with significant kidney disease are a specific exception, since impaired kidneys may not safely clear extra potassium, so anyone with a kidney condition should get individual advice before deliberately increasing potassium-rich foods.