Understanding TDS in Bottled Water

Total Dissolved Solids explained — what TDS means, how it's measured, the categories from very low to very high, the best TDS range for everyday drinking, and where every major bottled water brand sits on the scale.

What is TDS?

TDS (Total Dissolved Solids) is the combined concentration of all minerals, salts and trace elements dissolved in water, expressed in milligrams per liter (mg/L) or parts per million (ppm — equivalent for dilute aqueous solutions). It's the single most useful summary metric for "how mineralized is this water?"

In bottled mineral water, TDS is dominated by five players: calcium (Ca²⁺), magnesium (Mg²⁺), sodium (Na⁺), bicarbonate (HCO₃⁻) and sulphate (SO₄²⁻). Trace amounts of potassium, chloride, silica and others round out the rest.

How TDS is measured

Gravimetric (lab-grade). A measured water sample is evaporated to dryness in an oven at 180 °C, and the residue is weighed. This is the method behind the TDS values printed on bottle labels — accurate but slow.
Conductivity (field-grade). A handheld TDS meter measures the water's electrical conductivity in microsiemens (µS/cm) and applies a conversion factor (typically 0.5–0.7) to estimate TDS in ppm. Fast and cheap, but ±15% accuracy at best.

TDS categories

Category	TDS Range
Very Low	0–100 mg/L
Low	100–250 mg/L
Medium	250–500 mg/L
High	500–1,000 mg/L
Very High	1,000+ mg/L

Very Low — 0–100 mg/L

Ultra-soft, neutral palate. Closest to purified water in flavor. Negligible mineral contribution.

Spa · 33 Voss · 44 Poland Spring · 47 Icelandic Glacial · 70

Low — 100–250 mg/L

Soft, easy-drinking. Light mineral footprint. The most common bracket for everyday bottled spring waters.

Volvic · 130 Acqua Panna · 138 Highland Spring · 220 Fiji · 222

Medium — 250–500 mg/L

Noticeable mineral character. Crosses the FDA threshold (250 mg/L) for being labelled 'mineral water' in the US.

Buxton · 280 Evian · 357 Perrier · 475

High — 500–1,000 mg/L

Distinctly mineral-forward. Strong flavor, meaningful daily dose of calcium/magnesium/bicarbonate. Crosses the EU 'oligomineral' boundary.

Vittel · 841 San Pellegrino · 950

Very High — 1,000+ mg/L

EU 'high mineral content' category. Functional dose territory — used for bone health, athletic recovery and digestion. Often best consumed in smaller portions.

Badoit · 1,200 Ferrarelle · 1,346 Contrex · 2,078 Gerolsteiner · 2,500 Apollinaris · 2,650 Vichy Catalan · 3,052Borjomi · 6,000Donat Mg · 13,200

Best TDS range for drinking

For everyday hydration, 100–500 mg/L is the sweet spot — pleasant taste, meaningful nutritional minerals, no flavor overload. Below 100 mg/L tastes flat; above 1,500 mg/L crosses into functional territory better used in smaller portions.

The WHO has no upper TDS limit for health reasons — even Donat Mg at 13,200 mg/L is safe for consumption. Their 1,000 mg/L recommendation is taste-based, not safety-based.

Frequently Asked Questions

What does TDS mean in bottled water?

TDS (Total Dissolved Solids) is the combined concentration of all dissolved minerals, salts and trace elements in water, measured in milligrams per liter (mg/L). It's the single best summary number for how mineralized a bottled water is — higher TDS means more dissolved minerals.

How is TDS measured?

Two main methods. Lab-grade: evaporate a measured water sample to dryness and weigh the residue (the gravimetric method, mg/L). Field-grade: a TDS meter measures the water's electrical conductivity in microsiemens (µS/cm) and converts it to an estimated TDS in ppm. Conductivity meters are convenient but less accurate than gravimetric values reported on bottle labels.

What is the best TDS range for drinking water?

For everyday hydration, 100–500 mg/L is the sweet spot — enough minerals for a pleasant taste and meaningful nutritional contribution, without overwhelming flavor. Below 100 mg/L tastes flat; above 1,500 mg/L is functional/therapeutic territory better consumed in smaller doses. The WHO has no upper limit for TDS for health reasons (high-TDS mineral waters are safe), only a 1,000 mg/L taste-based recommendation.

Is low TDS water better than high TDS water?

Neither is universally 'better' — they serve different purposes. Low TDS waters (Aquafina, Voss, Spa) are neutral and easy-drinking. High TDS mineral waters (Gerolsteiner, Contrex, Donat Mg) deliver functional doses of calcium, magnesium and bicarbonate that purified water cannot. The best strategy for most people is rotating: a neutral low-TDS option for all-day hydration plus a high-TDS mineral water for targeted nutrition.

What is the TDS of tap water?

Tap water TDS varies enormously by region — typically 50–500 mg/L. Cities with limestone aquifers (London, Paris) sit at the high end; cities with surface-water supply (New York, Seattle) sit at the low end. Most tap water falls within the same TDS range as bottled spring water.

Pillar: Highest mineral content bottled water · Mineral content chart · Low mineral water