Convert conductivity between S/m, SI prefixes, S/cm, mS/cm, µS/cm, and legacy mho aliases, compare bulk-material and water-style scales.
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Electric conductivity converter Convert conductivity across metre-based SI prefixes, S/cm, mS/cm, µS/cm, and legacy mho aliases without losing the S/m baseline for materials and solution references.
Reference presets
How to read the result
Bulk materials are usually easiest to compare in S/m or SI prefixes of S/m, while electrolytes and water-quality readings are often reported in S/cm, mS/cm, or µS/cm.
Legacy mho notation is shown as an alias only: 1 mho/m equals 1 S/m, and 1 mho/cm equals 1 S/cm.
Enter a conductivity value Provide a value to compare the S/m baseline with material and solution-oriented conductivity references.
Electric conductivity converter: compare S/m, S/cm, mS/cm, and µS/cm scales
An electric conductivity converter rewrites one conductivity value across the bulk-material units common in engineering, the solution-oriented units used for electrolytes and water-quality measurements, and the older mho-per-length aliases that still appear in some references.
What this electric conductivity converter covers
This page converts a non-negative conductivity across S/m, mS/m, µS/m, nS/m, pS/m, kS/m, MS/m, S/cm, mS/cm, µS/cm, mho/m, and mho/cm.
The grouped layout separates metre-based SI prefixes, solution and water-quality centimetre scales, and legacy mho aliases so the same conductivity can be read in the form that best matches the source you are comparing against.
That matters because a conductivity value can look dramatically different depending on whether the source is written in metres or centimetres and whether SI prefixes are applied. The converter keeps those notation changes visible without changing the physical quantity itself.
S/m stays as the baseline
The converter first resolves the entered unit into siemens per metre. Every other value is then just the same conductivity expressed on a different scale or centimetre basis.
That baseline helps when you need to move between materials references and field readings without losing the actual magnitude behind the notation.
Once the S/m anchor is clear, the rest of the conversion is bookkeeping: larger engineering values may be easier to scan in kS/m or MS/m, while smaller solution readings are usually easier to scan in mS/cm or µS/cm.
1 kS/m = 1,000 S/m; 1 MS/m = 1,000,000 S/m
Large bulk-material conductivity values are often easier to scan in kS/m or MS/m.
Smaller metre-based SI prefixes keep low-conductivity material and insulation references readable.
1 S/cm = 100 S/m
Centimetre-based conductivity is the same quantity expressed against a shorter length basis.
1 mS/cm = 0.1 S/m; 1 µS/cm = 0.0001 S/m
These smaller solution-oriented scales are common in chemistry and water testing.
1 mho/m = 1 S/m; 1 mho/cm = 1 S/cm
Mho is an older reciprocal-ohm name and is treated here as a legacy alias for the corresponding siemens unit.
Expanded prefix and legacy coverage
Many simple conductivity calculators only handle one source unit and one target unit. This page keeps the full conversion sheet visible, so quick checks such as S/m to mS/cm, µS/cm to S/m, S/cm to S/m, and mho/cm to S/cm can be read together.
The metre-prefix rows are useful for materials work because very high-conductivity metals and very low-conductivity insulators may sit far apart on the same S/m baseline. The centimetre rows are more convenient for water, process, hydroponic, and electrolyte readings where µS/cm or mS/cm is the expected notation.
Mho per metre and mho per centimetre are included for legacy source compatibility, not because they are preferred modern SI names. When you control the notation, use siemens-based units.
Worked example: convert 1 mS/cm into S/m and µS/cm
Suppose a water or electrolyte reading is reported as 1 mS/cm. Because 1 mS/cm equals 0.1 S/m, the same conductivity is 0.1 S/m in metre-based SI form.
The same reading is also 1,000 µS/cm, because one millisiemens per centimetre is one thousand microsiemens per centimetre. This is a common search pattern when a field meter, specification sheet, and engineering note all use different conductivity scales.
Seeing all three values together helps you avoid a frequent unit-reading mistake: treating 1 mS/cm as if it were 1 S/m. Those are not the same magnitude, and the converter keeps the distinction explicit.
Why water-quality readings often mention specific conductance at 25°C
Water-quality and analytical references often report specific conductance or conductivity in µS/cm or mS/cm with a stated reference temperature, commonly 25°C. That is because conductivity can change materially with temperature even when the solution itself is otherwise the same.
A unit converter can rewrite the same stated value across S/m, S/cm, mS/cm, and µS/cm, but it does not perform temperature compensation. If one source is temperature-corrected and another is not, a pure unit conversion will not reconcile that difference by itself.
This is why conductivity conversion and conductivity interpretation are separate tasks. The first is about unit consistency. The second depends on measurement method, temperature basis, and solution chemistry.
Why conductivity is not the same as conductance or resistivity
Conductivity is a material or solution property per unit geometry. Conductance is the total ease of current flow for a particular path or device. Changing units here does not translate a material property into a whole-path electrical result.
That distinction matters because geometry, path length, electrode arrangement, and other setup details can materially change the measured conductance even when conductivity stays the same.
Resistivity is the reciprocal material property of conductivity. In ideal reciprocal form, higher conductivity means lower resistivity. This page surfaces the reciprocal resistivity as context, but it does not replace a dedicated resistivity workflow when you need specific engineering units or material tables.
What this converter does not model
This calculator does not estimate salinity, TDS, temperature compensation, resistivity, or whole-device conductance from a conductivity value. It converts the conductivity quantity itself between units only.
Use it as a planning and educational reference. If the next step depends on measurement setup, chemistry assumptions, or reciprocal resistivity, switch to the calculator that models those relationships directly.
It also does not tell you whether a conductivity level is good, bad, pure, contaminated, or acceptable for a process without the domain-specific context for that measurement. The meaning of a number depends on the material or solution being tested.
Frequently asked questions
How do I convert mS/cm to S/m?
Multiply by 0.1. One millisiemens per centimetre is exactly 0.1 siemens per metre, so 2 mS/cm becomes 0.2 S/m and 0.5 mS/cm becomes 0.05 S/m.
How do I convert µS/cm to mS/cm?
Divide by 1,000. Microsiemens per centimetre and millisiemens per centimetre are the same centimetre-based conductivity scale with different SI prefixes, so 750 µS/cm equals 0.75 mS/cm.
Why are mS/cm and µS/cm common in water testing?
Because many water and solution readings are small enough that centimetre-based millisiemens or microsiemens scales are more readable than the equivalent S/m values. Water-quality instruments and lab notes often use those smaller scales because they match the magnitude of the readings people see in practice.
Is conductivity the inverse of resistivity?
Yes in principle. Resistivity is the reciprocal of conductivity, so a higher conductivity implies a lower resistivity. This page can help you interpret that relationship, but it is still primarily a conductivity unit converter rather than a full resistivity-analysis tool.
Does this tell me total dissolved solids or salinity?
No. TDS and salinity estimates depend on calibration assumptions, meter settings, and solution chemistry. This page only converts conductivity units, so it does not infer dissolved solids or salinity from the number alone.
Is 1 mS/cm the same as 1 S/m?
No. 1 mS/cm equals 0.1 S/m. The centimetre basis and the milli prefix both matter, so reading those units as if they were interchangeable would overstate the conductivity by a factor of ten.
Why do some references say specific conductance instead of conductivity?
In water-quality work, specific conductance often means the conductivity reading adjusted to a reference temperature, commonly 25°C. The unit notation may still be µS/cm or mS/cm, but the measurement basis matters as much as the unit itself.
Can this converter compare copper-style conductivity tables with water readings?
It can compare the units cleanly, which is useful when one source is written in S/m and another in µS/cm. But it does not mean the numbers are directly comparable in purpose, because metals, solutions, and field measurements carry different interpretation context.
Can conductivity be negative?
Not in the standard physical sense used here. This converter treats conductivity as a non-negative quantity, so negative input is rejected as invalid.
What is mho per meter in a conductivity table?
Mho per meter is an older way to write siemens per meter. In this converter, 1 mho/m equals 1 S/m, and 1 mho/cm equals 1 S/cm. The mho rows are included so older references can be cross-checked without treating them as separate modern units.
When would I use µS/m, nS/m, or pS/m instead of µS/cm?
Use metre-based micro, nano, or pico prefixes when the source is a materials or insulation-style table that stays on a per-metre basis. Use µS/cm or mS/cm when the source is a water, electrolyte, or field-meter reading written on the centimetre basis.
Does this calculator apply temperature compensation?
No. It converts the stated conductivity value exactly as entered. If a reading is corrected to 25°C in one source and left uncorrected in another, a unit conversion alone will not resolve that difference.
When should I use the resistivity converter instead?
Use the resistivity converter when your source data or design notes are written in reciprocal property units such as Ω·m, Ω·cm, or conductor-style resistivity forms. This page is for conductivity-first workflows.
