vFluid Resistance

vCalc Reviewed
Equation / Last modified by AndrewS on 2016/11/09 15:28
vCalc.vFluid Resistance

This Fluid Resistance conversion equation converts an input measure of fluid resistance (pressure/volume) into other units of fluid resistance.  The pressure units are typically in pascals (Pa) or millimeters of mercury (mmHg), and the volume units range from cubic millimeter up to cubic meter.


To perform conversion:

  1. Enter the fluid resistance you wish to convert.  To do this, enter the value and choose the appropriate units for your input value.  When you do, the results will be displayed in the default fluid resistance units.
  2. Then, use the pull-down menu on the results window to change the output units to your desired converted units.

For example: if you enter 205.8 and leave the default input units as `("Pa"*s)"/"L` as your input fluid resistance unit, the display will show a resultant 205.8 `("Pa"*s)"/"L` output.  If you then select `("mmHG" * "min")" / cm"^3` as your output units, the output is automatically converted to 0.0000257271868108789 `("mmHG" * "min") / "cm"^3`.

Example: if you enter 1000 and select `("mmHG" * s)"/"L` as input units, you can convert to `("Pa"*"min") "/" L` by simply selecting `("Pa"*"min") "/" L` as the output unit. vCalc would convert 1000 to 2222.03333333333  `("Pa"*"min") / L`


Fluid Resistance is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. Fluid Resistance is sometimes referred to as drag (or air resistance when the fluid is air) or fluid friction. The effects of fluid resistance may be exhibited between fluid layers or fluid surfaces or between a fluid and a solid surface.

Fluid resistance depends on velocity. Drag force is proportional to the velocity for a laminar flow and the squared velocity for a turbulent flow and the cause of fluid resistance is viscous friction.

Fluid Resistance decreases fluid velocity relative to a solid object with which the fluid interacts.some

The units of fluid resistance supported by vCalc for conversion are:

  • `(Pa * s) /L` (Pascal second per Liter)
  • `(Pa * "min") /L` (Pascal minute per Liter)
  • `(Pa * s) /"mL"` (Pascal second per milliliter)
  • `(Pa * "min") /L` (Pascal minute per milliliter)
  • `(Pa * s) /m^3` (Pascal second per cubic meter)
  • `(Pa * "min") /m^3` (Pascal minute per cubic meter)
  • `(Pa * s) /"cm"^3` (Pascal second per cubic centimeter)
  • `(Pa * "min") /"cm"^3` (Pascal minute per cubic centimeter)
  • `("mmHg" * s) /L` (millimeter Mercury second per Liter)
  • `("mmHg" * "min") /L` (millimeter Mercury minute per Liter)
  • `("mmHg" * s) /mL` (millimeter Mercury second per milliliter)
  • `("mmHg" * "min") /L` (millimeter Mercury minute per milliliter)
  • `("mmHg" * s) /"cm"^3` (millimeter Mercury second per cubic centimeter )
  • `("mmHg" * "min") /"cm"^3` (millimeter Mercury minute per cubic centimeter )

See also: