Authoritative definitions of the International System of Units and SI prefixes.
Dedicated unit pair
Stokes to Square millimetres per second
Convert St to mm²/s instantly, then review the formula, assumptions, and rounding guidance.
ViscosityInstant result
Decimals
Formula result = input × 0.0001 ÷ 0.000001. 1 St = 100 mm²/s
Common examples
One value, several units
Square metres per second0.0001 m²/s
Square millimetres per second100 mm²/s
Centistokes100 cSt
Square feet per second0.0011 ft²/s
Conversion table
| St | mm²/s |
|---|---|
| 1 St | 100 mm²/s |
| 2 St | 200 mm²/s |
| 5 St | 500 mm²/s |
| 10 St | 1,000 mm²/s |
| 25 St | 2,500 mm²/s |
| 50 St | 5,000 mm²/s |
| 100 St | 10,000 mm²/s |
Conversion chart
1 St100 mm²/s
5 St500 mm²/s
10 St1,000 mm²/s
25 St2,500 mm²/s
50 St5,000 mm²/s
Worked example
1 cSt equals 1 mm²/s.
Unit definition
Stokes (St) One stokes equals 0.0001 square metre per second.
Unit history
Stokes is represented here using its modern SI definition or an internationally accepted relationship to an SI base unit.
Step by step
1. Parse the value, including fractions.
2. Convert St to square metre per second.
3. Convert the base value to mm²/s and apply your display precision.
Understand the result before using it
Stokes to Square millimetres per second converts a value measured in Stokes (St) into the equivalent value in Square millimetres per second (mm²/s). The numerical value changes because the size and definition of the selected unit changes; the underlying quantity does not.
Calculated result
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.
Formula, assumptions, and example
Formula
result = input × 0.0001 ÷ 0.000001
Assumptions
- Stokes and Square millimetres per second represent the same kinematic viscosity quantity.
- The input is expressed in St; the output is expressed in mm²/s.
- The unit definitions and conventional relationship shown on this page apply.
Worked example
1 St = 100 mm²/s. For another value, apply the same relationship and round only to the precision your source measurement supports.
When to use it
Good uses
- Read a St measurement in a document that expects mm²/s.
- Compare a stokes value with a value reported in square millimetres per second.
- Check the St-to-mm²/s arithmetic before copying the result into another calculation.
Limitations
Common mistakes to avoid
- Dynamic and kinematic viscosity are different quantities and require density to convert between each other.
- Round the output to a precision justified by the original measurement.
- Verify safety-critical, regulated, laboratory, and contractual conversions against the controlling standard.
Sources and further reading
These references explain the underlying standards or provide authoritative context. Your own contract, institution, clinician, product documentation, local code, or governing standard may be the controlling source.
Guidance on unit names, symbols, conversions, and numerical presentation.
Questions about this calculation
How do I convert Stokes to Square millimetres per second?
result = input × 0.0001 ÷ 0.000001 Using the displayed relationship, 1 St equals 100 mm²/s.
How many Square millimetres per second are in one Stokes?
One Stokes is 100 Square millimetres per second. The displayed digits may be rounded.
Can I reverse the St to mm²/s conversion?
Yes. Swap the source and target units in the converter. The reverse relationship converts mm²/s back to St.
Is the Stokes to Square millimetres per second result exact?
The conversion follows the displayed unit relationship. Display rounding can hide additional digits, and measured inputs cannot become more accurate merely by changing units.