How Much Sodium in Baking Soda Water? Per 1/4 Tsp Glass

A 1/4 tsp glass holds about 315 mg of sodium. Here are the numbers for 1/8 to 1 tsp, a table salt comparison and who should ask a doctor first.

The pages we opened on this question give no per-glass figure, so we calculated it and show the work below. Baking soda is sodium bicarbonate, and sodium is the whole story of this glass. We found no source showing that it burns fat or helps you lose weight, and this page makes no health promise.

The dose chart, label limits and water minimum live in how much baking soda in water, and the risks live in baking soda side effects. We link to them instead of repeating their tables. If weight is why you're here, start with does baking soda help you lose weight.

The Food Science / Lab Kitchen Note

Sodium bicarbonate is about 27% sodium by mass. USDA FoodData Central lists baking soda at 27,360 mg of sodium per 100 g, which is 273.6 mg per gram. That per-gram figure is the only constant you need.

The formula: grams of baking soda x 273.6 mg per gram = mg of sodium. For 1/4 tsp, that's 1.15 g x 273.6 = about 315 mg.

Two caveats. USDA gives a household portion of 4.6 g for 1 tsp and 2.3 g for 1/2 tsp. The weights for 1/8 and 1/4 tsp are our division of that 4.6 g teaspoon, not USDA portions. And the 100 g basis is our assumption, because the USDA page doesn't print it.

The spoon matters too. Only a level teaspoon gives the 4.6 g weight. A heaped spoon holds more powder and more sodium, so level it with a knife.

Sodium per spoon: 1/8 to 1 teaspoon

The FDA puts the sodium Daily Value at less than 2,300 mg per day, and says Americans average about 3,400 mg. The American Heart Association says most adults should eat no more than 2,300 mg a day, and names 1,500 mg as the ideal limit for most adults, especially people with high blood pressure. All figures below are our calculation at 273.6 mg per gram.

That sodium arrives on top of everything else you eat that day. The FDA links too much sodium to high blood pressure, heart attack, heart failure, stroke, kidney disease and blindness.

Three sources of sodium compared (data only)

This is a comparison of published and calculated data, not a taste test or a trial of our own. So, is baking soda high in sodium? Weight for weight, baking soda has about 71% of the sodium in table salt (273.6 against 387.6 mg per gram). But a teaspoon of salt weighs more than a teaspoon of soda, so the spoon comparison looks different.

A level teaspoon of baking soda (about 1,259 mg) carries about 54% of the sodium in a teaspoon of table salt. Our 315 mg glass equals about 39 g of dill pickle, or about 46 g of undiluted, condensed canned chicken noodle soup (681 mg per 100 g, USDA). The salt figure is 6 g x 387.58 mg per gram, our calculation.

How baking soda compares with baking powder: no sourced data. They are different products, so we don't mix them.

The sports dose is a separate thing. The ISSN position stand, a consensus statement from 2021, names 0.3 g per kilogram of body weight as the optimal single dose and 0.2 g/kg as the minimum effective dose, taken 60 to 180 minutes before exercise. At 70 kg that is 14 to 21 g by our arithmetic, about 12 to 18 times the 1.15 g in our glass. It's an athletic protocol with bloating, nausea, vomiting and abdominal pain as listed side effects. It is never the recipe dose.

What the studies show

Searches for this topic often assume baking soda water does something to blood pressure or the body at large. The best controlled evidence we found comes from kidney patients, and it should be read that way.

The BiCARB trial (BMC Medicine, 2020) was a double-blind, placebo-controlled randomized trial of 300 adults aged 60 or older with advanced chronic kidney disease and low blood bicarbonate. They took 1.5 to 3 g a day of sodium bicarbonate tablets for up to 2 years. It found no effect on blood pressure (systolic difference 0 mmHg, 95% CI -4 to 3), no benefit on physical or kidney function, and more adverse events (457 against 400). The people in it were patients under medical care, not healthy cooks, so it's no dose guide for a kitchen glass.

A systematic review and meta-analysis of randomized trials (CJASN, 2023) pooled 14 trials and 2,110 adults with non-dialysis chronic kidney disease, using a median of 0.5 mEq/kg of oral sodium bicarbonate. It found no significant difference in systolic blood pressure against control (moderate certainty) and no higher need for blood pressure medicines. Again, the population is kidney-disease patients dosed under a doctor's care. Neither study tested people in good health, and neither tested a weight-loss claim.

Common mistakes

Heaping the spoon. Sodium scales with the powder. A heaped teaspoon holds more than the 4.6 g that USDA's figure assumes, so level it.

Skipping the dissolve. Undissolved powder is the usual slip. The label says not to drink it until it is completely dissolved, and never in less than 4 fl oz (120 mL) of water per MedlinePlus.

Counting only the glass. 315 mg looks small, and it is 14% of the daily limit before breakfast has started. Add it to the rest of your day.

Substitutes and swaps

Storage

Mix one glass and drink it. We found no sourced shelf life for the mixed drink, so we give no duration. Make-ahead tip: measure the dry soda into the spoon, level it, and add water only when you're ready to drink.

Nutrition note

Values on the recipe card are estimates calculated from typical USDA FoodData Central values for baking soda, per glass of 8 fl oz with 1/4 tsp (1.15 g), not measured. The glass is water and baking soda, so calories, carbohydrate, protein, fat, sugars and fiber are all zero. Sodium is about 315 mg, or 13.7% of 2,300 mg. For timing, see the best time to drink baking soda water, and for a flavored version, baking soda and lemon water.