Millisiemens per centimeter to parts per million
Type a value in mS/cm to get it in ppm instantly.
That's 7.1× as pure as seawater — nothing on our list beats it. That is above drinking water guidelines and heading towards brackish.
What it means
How pure is that water?
A TDS meter does not measure solids. It measures conductivity and multiplies, so anything dissolved that does not conduct — sugar, for instance — is invisible to it.
The math
How to convert mS/cm to ppm
A TDS meter multiplies conductivity by a fixed factor: ppm = µS/cm × scale, where the scale is 0.5 for NaCl, 0.64 for hydroponics and 0.7 for 442. The figures below use the scale selected above.
Example: 500 mS/cm = 250,000 ppm.
The table below uses NaCl scale (× 0.5).
Every unit
Your reading in every unit
Tables
mS/cm to ppm conversion table
| mS/cm | ppm |
|---|---|
| 10 mS/cm | 5,000 ppm |
| 50 mS/cm | 25,000 ppm |
| 100 mS/cm | 50,000 ppm |
| 250 mS/cm | 125,000 ppm |
| 500 mS/cm | 250,000 ppm |
| 800 mS/cm | 400,000 ppm |
| 1,000 mS/cm | 500,000 ppm |
| 1,500 mS/cm | 750,000 ppm |
| 3,000 mS/cm | 1,500,000 ppm |
| 10,000 mS/cm | 5,000,000 ppm |
| 35,000 mS/cm | 17,500,000 ppm |
ppm to mS/cm conversion table
| ppm | mS/cm |
|---|---|
| 10 ppm | 0.02 mS/cm |
| 50 ppm | 0.1 mS/cm |
| 100 ppm | 0.2 mS/cm |
| 250 ppm | 0.5 mS/cm |
| 500 ppm | 1 mS/cm |
| 800 ppm | 1.6 mS/cm |
| 1,000 ppm | 2 mS/cm |
| 1,500 ppm | 3 mS/cm |
| 3,000 ppm | 6 mS/cm |
| 10,000 ppm | 20 mS/cm |
| 35,000 ppm | 70 mS/cm |
Quick answers
Quick answers
- How many ppm is 1 mS/cm?
- 1 mS/cm is 500 ppm.
- How many ppm is 10 mS/cm?
- 10 mS/cm is 5,000 ppm.
- How many ppm is 500 mS/cm?
- 500 mS/cm is 250,000 ppm.
The units
About these units
Millisiemens per centimeter (mS/cm)
A thousand µS/cm, used in hydroponics and seawater.
Parts per million (ppm)
Total dissolved solids, as a TDS meter reports it.
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