Salinity Converter
Convert between ppt, PSU, specific gravity, and conductivity for aquarium and marine use.
Type in any field — the others update instantly. Values are approximate at 25°C.
Salinity measures the dissolved salt content in water.
Common units:
- ppt (parts per thousand) — grams of salt per kilogram of water
- PSU (Practical Salinity Units) — dimensionless, numerically equal to ppt
- Specific Gravity (SG) — density compared to pure water (1.000)
- Conductivity (mS/cm) — electrical conductivity at 25°C
Conversions (approximate):
- ppt ≈ PSU (for practical purposes, they are interchangeable)
- SG ≈ 1 + (ppt × 0.0008) (at 25°C)
- Conductivity ≈ ppt × 1.4118 mS/cm (approximate, varies with temperature)
Reference values:
| Water Type | ppt / PSU | Specific Gravity | Conductivity |
|---|---|---|---|
| Fresh water | 0–0.5 | 1.000 | 0–0.7 mS/cm |
| Brackish water | 0.5–30 | 1.000–1.024 | 0.7–42 mS/cm |
| Ocean water | 33–37 | 1.024–1.028 | 47–52 mS/cm |
| Reef aquarium | 34–36 | 1.025–1.027 | 48–51 mS/cm |
| Dead Sea | ~340 | ~1.240 | ~192 mS/cm |
These conversions are approximate. Exact values depend on temperature, pressure, and ionic composition.