Mineral water guide
Mineral Water Content: Calcium, Magnesium, Sodium, Bicarbonate and TDS Explained
Every mineral water label lists the same handful of numbers: TDS, calcium, magnesium, sodium and bicarbonate. Here is what each one means, the ranges that matter, and how to read a mineral water label like a pro.
TDS (Total Dissolved Solids)
TDS is the total weight of everything dissolved in the water, in milligrams per liter. Under 50 mg/L = very low (purified, Smartwater). 50–500 = low to medium (Evian, FIJI). 500–1,500 = high mineral (San Pellegrino). Above 1,500 = very high mineral (Gerolsteiner, Vichy Catalan). Higher TDS does not mean unsafe — it means more dissolved minerals. See lowest-TDS brands and highest-TDS brands.
Calcium
Calcium supports bones, teeth and muscle function. Adult RDA is 1,000 mg/day. Mineral water can deliver 80–400 mg per liter — meaningful contribution. Top sources: Gerolsteiner (~348 mg/L), Vittel (~240 mg/L), Evian (~80 mg/L), Contrex (~468 mg/L). See highest-calcium waters.
Magnesium
Magnesium is involved in 300+ enzymatic reactions and is widely under-consumed. Adult RDA: 320–420 mg/day. Magnesium from water is highly bioavailable. Top sources: Gerolsteiner (~108 mg/L), San Pellegrino (~49.5 mg/L), Mg-fortified brands like Donat Mg (~1,000 mg/L). See highest-magnesium waters.
Sodium
Sodium content varies wildly. Low-sodium waters (under 20 mg/L): Evian, Volvic, Mountain Valley. Medium: Fiji (~16 mg/L), San Pellegrino (~31.2 mg/L). High: Gerolsteiner (~118 mg/L), Vichy Catalan (~1,100 mg/L). If you're on a sodium-restricted diet, check our lowest-sodium picks.
Bicarbonate
Bicarbonate (HCO₃⁻) is the buffer that gives mineral water its smooth, slightly sweet, alkaline character. It can help with acid reflux and post-exercise pH balance. High-bicarbonate brands: Gerolsteiner (~1,816 mg/L), Vichy Catalan (~2,100 mg/L), Borjomi (~3,500 mg/L). See waters with the most bicarbonate.
How to read a mineral water label
- Find the analysis panel — usually on the back, in mg/L.
- Check TDS or "dry residue at 180°C" first for an overall feel.
- Look at calcium + magnesium for nutritional contribution.
- Check sodium against your dietary needs.
- Bicarbonate hints at mouthfeel and alkalinity.
Quick comparison
| Brand | TDS | Ca | Mg | Na | HCO₃ |
|---|---|---|---|---|---|
| Gerolsteiner | 2,479 | 345 | 100 | 115 | 1,816 |
| San Pellegrino | 960 | 178 | 53 | 36 | 219 |
| Evian | 309 | 80 | 26 | 5 | 360 |
| FIJI | 222 | 18 | 15 | 18 | 154 |
Frequently asked questions
What's a healthy TDS for drinking water?
Anywhere from 50–1,500 mg/L is fine for healthy adults. The WHO has no upper limit on TDS for safety, only palatability.
Which mineral matters most in water?
For most people, magnesium — it's the one most diets fall short on, and water-borne magnesium is highly bioavailable.
Is high bicarbonate water good for you?
It can help neutralize stomach acid and buffer exercise-induced lactic acid. Generally safe; people on sodium-restricted diets should check the sodium content alongside.
Does sparkling water count as mineral water?
Only if it's naturally mineral water with natural carbonation, like Gerolsteiner or San Pellegrino. Brands like Perrier or La Croix are different categories.
Instant PDF. Every major brand ranked by pH, minerals, source and taste.
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