convertimate Water TDS

Microsiemens per centimeter to parts per million

Type a value in µS/cm to get it in ppm instantly.

250ppm

That's about the same as ordinary tap water. That is good drinking water, low in minerals.

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 µS/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 µS/cm = 250 ppm.

The table below uses NaCl scale (× 0.5).

Every unit

Your reading in every unit

Tables

µS/cm to ppm conversion table

µS/cm to ppm conversion table
µS/cmppm
10 µS/cm5 ppm
50 µS/cm25 ppm
100 µS/cm50 ppm
250 µS/cm125 ppm
500 µS/cm250 ppm
800 µS/cm400 ppm
1,000 µS/cm500 ppm
1,500 µS/cm750 ppm
3,000 µS/cm1,500 ppm
10,000 µS/cm5,000 ppm
35,000 µS/cm17,500 ppm
ppm to µS/cm conversion table
ppm to µS/cm conversion table
ppmµS/cm
10 ppm20 µS/cm
50 ppm100 µS/cm
100 ppm200 µS/cm
250 ppm500 µS/cm
500 ppm1,000 µS/cm
800 ppm1,600 µS/cm
1,000 ppm2,000 µS/cm
1,500 ppm3,000 µS/cm
3,000 ppm6,000 µS/cm
10,000 ppm20,000 µS/cm
35,000 ppm70,000 µS/cm

Quick answers

Quick answers

How many ppm is 1 µS/cm?
1 µS/cm is 0.5 ppm.
How many ppm is 10 µS/cm?
10 µS/cm is 5 ppm.
How many ppm is 500 µS/cm?
500 µS/cm is 250 ppm.

The units

About these units

Microsiemens per centimeter (µS/cm)

Conductivity, which is what the probe actually measures.

Parts per million (ppm)

Total dissolved solids, as a TDS meter reports it.

Learn more about dissolved solids units

Keep going

Related conversions