Electrical Conductivity Converter

This electrical conductivity converter changes conductivity between siemens per meter, siemens per centimeter, millisiemens per centimeter and absiemens per centimeter. Formula: 1 mS/cm = 0.1 S/m; 1 µS/cm = 0.0001 S/m. The SI unit is S/m. 1 S/cm is exactly 100 S/m and 1 mS/cm is exactly 0.1 S/m, so 1 µS/cm is 0.0001 S/m.

How to use the electrical conductivity converter

1. Enter the value, for example 1.5 from a conductivity meter in mS/cm.
2. In the electrical conductivity converter, choose its unit and the target unit, such as mS/cm to S/m.
3. Read the electrical conductivity converter result: 1.5 mS/cm = 0.15 S/m.

For mS/cm to S/m, divide by 10. For µS/cm to mS/cm, divide by 1,000. For S/m to µS/cm, multiply by 10,000.

What is electrical conductivity?

Electrical conductivity is a material property describing how well it conducts current, independent of shape. The SI unit is the siemens per meter (S/m). Water quality meters often report microsiemens or millisiemens per centimeter.

Conversion formula

The electrical conductivity converter stores every unit as a multiple of the base unit, the siemens per meter (S/m). To convert:

value in target unit = value × (factor of source unit ÷ factor of target unit)

where each factor is the size of the unit in siemens per meter.

Common electrical conductivity conversions

From	To	1 unit equals
siemens per meter (S/m)	siemens per centimeter (S/cm)	0.01 S/cm
millisiemens per centimeter (mS/cm)	siemens per meter (S/m)	0.1 S/m

Electrical conductivity converter worked example

Convert 25 siemens per meter to siemens per centimeter:

1. Factor of S/m = 1 S/m
2. Factor of S/cm = 100 S/m
3. 25 × 1 ÷ 100 = 0.25 S/cm

Electrical conductivity unit reference

Unit	Symbol	Group	Equals (S/m)
Siemens per Meter	S/m	SI	1
Siemens per Centimeter	S/cm	SI	100
Millisiemens per Centimeter	mS/cm	Practical	0.1
Absiemens per Centimeter	abS/cm	CGS-EMU	100,000,000,000

Reverse factors for each electrical conductivity unit

The reference table gives each unit in siemens per meters. To go the other way, divide by that factor; the list below does the division for you.

• Siemens per Centimeter (S/cm), SI: 1 S/cm = 100 S/m, so 1 S/m = 0.01 S/cm.
• Millisiemens per Centimeter (mS/cm), Practical: 1 mS/cm = 0.1 S/m, so 1 S/m = 10 mS/cm.
• Absiemens per Centimeter (abS/cm), CGS-EMU: 1 abS/cm = 1 × 10¹¹ S/m, so 1 S/m = 1 × 10⁻¹¹ abS/cm.

Water conductivity in µS/cm, mS/cm and S/m

Water quality work reports specific conductance in µS/cm at 25 °C. The USGS gives a typical range for US streams of about 50 to 1,500 µS/cm:

Sample	µS/cm	mS/cm	S/m
Ultrapure water at 25 °C	0.055	0.000055	0.0000055
Low end of US streams (USGS)	50	0.05	0.005
High end of US streams (USGS)	1,500	1.5	0.15

Seawater is far higher, in the tens of mS/cm. Conductivity rises about 2% per °C, which is why meters compensate to 25 °C.

Conductivity of metals

Metals are measured in MS/m. 100% IACS, the annealed copper standard, is 58 MS/m, or 580,000 S/cm. Conductivity is the reciprocal of resistivity, σ = 1 ÷ ρ, so the IACS copper resistivity is 1/58 Ω·mm²/m ≈ 1.7241 × 10⁻⁸ Ω·m. Use the electrical resistivity converter for the reciprocal and the electrical conductance converter for whole components in siemens.

Conductivity and dissolved solids

Water quality meters read conductivity in µS/cm, while SI references use mS/m or S/m. 1 mS/m equals 10 µS/cm. The electrical conductivity converter handles both directions.

Many meters estimate total dissolved solids by multiplying µS/cm by a factor between about 0.5 and 0.7. A reading of 400 µS/cm suggests roughly 200 to 280 mg/L TDS. The exact factor depends on which salts are present, so labs measure TDS directly when it matters.

Seawater is around 50,000 µS/cm, or 5 S/m, while distilled water is a few µS/cm or less. Conductivity rises about 2% per °C, so meters correct to 25 °C.

Hydroponic growers often use EC in mS/cm, where 1 mS/cm equals 1,000 µS/cm; nutrient mixes commonly run around 1 to 2.5 mS/cm depending on the crop. Pool and aquarium keepers use the same meters, so knowing that 1.5 mS/cm, 1,500 µS/cm and 150 mS/m are all the same reading saves a lot of confusion when comparing guides from different countries.

Related converters and calculators

Related electrical tools:

• Electrical resistivity converter: Ω·m and Ω·cm
• Electrical conductance converter: S and µS
• Electrical resistance converter: Ω, kΩ, MΩ
• Mass concentration converter: mg/L and ppm
• Current density converter: A/m²

Sources

NIST Special Publication 811, Appendix B; USGS Water Science School: Conductivity and water.

Questions about this calculator