Fluids & Transport

Advanced Fluids & Transport Unit Converter

Convert fluid flow and transport quantities including Flow Rate, CFM, Mass Flow, Molar Flow, Viscosity, Surface Tension, Permeability, Density, Pressure Drop, Diffusion Coefficient, Thermal Conductivity, Heat Transfer Coefficient, plus common dimensionless numbers like Reynolds, Mach, Prandtl, Schmidt and Froude.

ν = μ/ρ Re = ρVD/μ Mach = V/a Pr = ν/α Sc = ν/D 1 CFM = 0.000471947 m³/s
SI base units

Most categories use SI base units (m³/s, kg/s, mol/s, Pa·s, m²/s, N/m, kg/m³, Pa) then convert to common engineering units.

Numbers vs units

Reynolds, Mach, Prandtl, Schmidt and Froude are dimensionless. This tool converts "value labels" (same number) and explains formulas.

Pressure drop context

Pressure drop depends on geometry and flow regime. This page converts pressure units, not pipe or duct models.

Interactive Converter

Pick a category, choose units, enter a value, then copy the result. Use Swap to reverse units.

Category explanation
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Select a category to see what it means and where it is used.

Base unit: —
Plain language

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Common formula

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Real world uses

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Tip: You can type commas (like 10,000). The converter reads it as 10000.

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Enter a value to convert
Conversion Formula
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Notes: Dimensionless numbers (Re, Mach, Pr, Sc, Fr) do not "convert" in the usual sense. This page keeps the value the same and explains the formula.

Quick Reference: Common Conversions

Quick lookup table for the most frequently used fluid and transport unit conversions.

Quantity From To Conversion Factor
Volumetric Flow CFM m³/s × 0.000472
Volumetric Flow gpm L/min × 3.785
Dynamic Viscosity cP Pa·s × 0.001
Kinematic Viscosity cSt m²/s × 1e-6
Surface Tension dyne/cm N/m × 0.001
Density g/cm³ kg/m³ × 1000
Pressure Drop psi Pa × 6894.76
Pressure Drop inH₂O Pa × 249.09
Diffusion Coefficient cm²/s m²/s × 1e-4
Permeability mD m² × 9.87e-16

Worked Examples

Pre computed examples help visitors learn magnitudes and verify conversions quickly.

Example: Volumetric Flow

Convert 250 CFM to m³/s.

Result: —

Common in HVAC and ventilation systems.

Example: Dynamic Viscosity

Convert 12 cP to Pa·s.

Result: —

Water at room temp is approximately 1 cP.

Example: Surface Tension

Convert 72 mN/m to lbf/ft.

Result: —

Water surface tension at 20°C.

Example: Reynolds Number

Water flow in a pipe: Re = 5000 (turbulent).

Interpretation: Fully developed turbulent flow regime.

Critical Re ≈ 2300 for pipes.

Example: Molar Concentration

Convert 0.5 mol/L to mol/m³.

Result: —

Common in chemistry and biochemistry.

Example: Thermal Conductivity

Convert 0.6 W/(m·K) to Btu/(h·ft·°F).

Result: —

Typical for insulation materials.

FAQ

Dynamic vs kinematic viscosity?

Dynamic viscosity μ is in Pa·s. Kinematic viscosity ν is in m²/s and equals ν = μ/ρ.

How do CFM and m³/s convert?

1 CFM = 0.00047194745 m³/s (cubic feet per minute to cubic meters per second).

Do dimensionless numbers convert?

Reynolds, Mach, Prandtl, Schmidt and Froude are dimensionless. The numeric value stays the same, but this page explains their formulas and inputs.

What is the relationship between density and specific volume?

Specific volume v = 1/ρ. They are reciprocals. If density is 1000 kg/m³, specific volume is 0.001 m³/kg.

How is mass flow related to volumetric flow?

ṁ = ρ × Q. Mass flow is density times volumetric flow. This relationship is critical in compressible flow.

What is Prandtl number used for?

Prandtl number Pr = ν/α compares momentum diffusivity to thermal diffusivity. It is used in convection heat transfer correlations.