What is the Fluids Converter?
The Fluids Converter is a comprehensive online tool for converting between various fluid property measurements across 10 major categories: Flow, Flow - Molar, Concentration - Molar, Viscosity - Dynamic, Surface Tension, Flow - Mass, Mass Flux Density, Concentration - Solution, Viscosity - Kinematic, and Permeability. With 98+ units, this converter is essential for chemical engineers, petroleum engineers, fluid dynamics researchers, and laboratory professionals.
Categories and Units
1. Flow (18 units)
Volumetric Flow Rate measures the volume of fluid passing through a cross-section per unit time. Essential for pipeline design, HVAC systems, and process engineering.
- Cubic Meter/Second (m³/s) - SI unit
- Liter/Second (L/s) - Common in water systems
- Liter/Minute (L/min) - Used in pumps and medical equipment
- Gallon (US)/Minute (gal/min) - Common in US plumbing
- Cubic Foot/Second (ft³/s) - Used in river flow measurements
- Barrel/Day (bbl/day) - Petroleum industry standard
- Plus: m³/h, m³/min, L/h, mL/s, mL/min, ft³/min, ft³/h, gal(US)/s, gal(US)/h, gal(UK)/s, gal(UK)/min, gal(UK)/h
2. Flow - Molar (9 units)
Molar Flow Rate measures the amount of substance (in moles) passing through per unit time. Critical for chemical reactions and process control.
- Mole/Second (mol/s) - SI unit
- Kilomole/Hour (kmol/h) - Common in chemical plants
- Millimole/Minute (mmol/min) - Laboratory scale
- Plus: mol/min, mol/h, kmol/s, kmol/min, mmol/s, mmol/h
3. Concentration - Molar (8 units)
Molar Concentration measures the amount of substance per unit volume. Fundamental in chemistry and biochemistry.
- Mole/Liter (mol/L) - Molarity (M), standard in chemistry
- Millimole/Liter (mmol/L) - Medical laboratory standard
- Micromole/Liter (μmol/L) - Trace analysis
- Nanomole/Liter (nmol/L) - Ultra-trace analysis
- Plus: mol/m³, mol/mL, kmol/m³, mmol/mL
Example: A 1 M (molar) solution contains 1 mole of solute per liter of solution.
4. Viscosity - Dynamic (11 units)
Dynamic Viscosity measures a fluid's resistance to flow. Critical for lubricant selection, pipeline design, and fluid mechanics.
- Pascal Second (Pa·s) - SI unit
- Centipoise (cP) - Most common unit (1 cP = 1 mPa·s)
- Poise (P) - CGS unit (1 P = 0.1 Pa·s)
- Plus: N·s/m², mPa·s, μPa·s, dyne·s/cm², kgf·s/m², lbf·s/ft², lb/(ft·s), lb/(ft·h)
Common viscosities:
- Water at 20°C: ~1 cP
- Olive oil: ~80 cP
- Honey: ~10,000 cP
- Motor oil SAE 30: ~200 cP at 100°C
5. Surface Tension (7 units)
Surface Tension measures the force acting along the surface of a liquid. Important in coating processes, droplet formation, and capillary action.
- Newton/Meter (N/m) - SI unit
- Millinewton/Meter (mN/m) - Common in practice
- Dyne/Centimeter (dyne/cm) - CGS unit (1 dyne/cm = 1 mN/m)
- Plus: erg/cm², lbf/in, lbf/ft, pdl/in
Example: Water at 20°C has a surface tension of ~72.8 mN/m.
6. Flow - Mass (12 units)
Mass Flow Rate measures the mass of fluid passing through per unit time. Essential for mass balance calculations and process control.
- Kilogram/Second (kg/s) - SI unit
- Pound/Minute (lb/min) - Common in US industry
- Metric Ton/Hour (t/h) - Large-scale processes
- Plus: kg/min, kg/h, g/s, g/min, g/h, mg/s, lb/s, lb/h, ton(US)/h
7. Mass Flux Density (7 units)
Mass Flux Density measures the mass flow rate per unit area. Used in heat and mass transfer calculations.
- Kilogram/(Square Meter·Second) [kg/(m²·s)] - SI unit
- Gram/(Square Centimeter·Second) [g/(cm²·s)] - CGS unit
- Plus: kg/(m²·h), g/(m²·h), lb/(ft²·s), lb/(ft²·h), lb/(in²·s)
8. Concentration - Solution (11 units)
Solution Concentration measures mass of solute per unit volume. Common in environmental analysis and quality control.
- Kilogram/Cubic Meter (kg/m³) - SI unit
- Gram/Liter (g/L) - Common in chemistry
- Milligram/Liter (mg/L) - Parts per million (ppm) for water
- Microgram/Liter (μg/L) - Parts per billion (ppb) for water
- Plus: g/mL, mg/mL, μg/mL, ng/L, lb/ft³, lb/gal(US), oz/gal(US)
Note: For water, 1 mg/L ≈ 1 ppm (parts per million).
9. Viscosity - Kinematic (7 units)
Kinematic Viscosity is the ratio of dynamic viscosity to density. Used in fluid flow calculations and lubricant specifications.
- Square Meter/Second (m²/s) - SI unit
- Stokes (St) - CGS unit (1 St = 0.0001 m²/s)
- Centistokes (cSt) - Most common unit (1 cSt = 1 mm²/s)
- Plus: cm²/s, mm²/s, ft²/s, in²/s
Relationship: Kinematic Viscosity = Dynamic Viscosity / Density
Example: Water at 20°C has a kinematic viscosity of ~1 cSt.
10. Permeability (8 units)
Permeability measures a material's ability to allow fluids to pass through it. Critical in petroleum engineering, hydrogeology, and filtration.
- Square Meter (m²) - SI unit
- Darcy (D) - Petroleum industry standard (1 D = 9.869 × 10⁻¹³ m²)
- Millidarcy (mD) - Most common in oil/gas (1 mD = 0.001 D)
- Plus: cm², mm², μm², ft², in²
Typical permeabilities:
- Sandstone reservoir: 10-1000 mD
- Limestone: 1-100 mD
- Shale: <0.001 mD
How to Use the Fluids Converter
- Select Category: Choose from 10 fluid property categories
- Enter Value: Type the numerical value you want to convert
- Select From Unit: Choose the unit you're converting from
- Select To Unit: Choose the unit you're converting to
- Click Convert: Get instant results with 6 decimal precision
Common Use Cases
Chemical Engineering
Convert molar flow rates for reactor design. Calculate concentrations for process control. Determine viscosity requirements for mixing operations.
Petroleum Engineering
Convert permeability between darcy and millidarcy for reservoir characterization. Calculate flow rates in barrels per day for production forecasting.
Environmental Engineering
Convert pollutant concentrations from mg/L to ppm. Calculate mass flux for emission monitoring. Determine flow rates for water treatment systems.
Laboratory Work
Prepare solutions with specific molar concentrations. Convert between molarity units for different protocols. Calculate reagent flow rates for experiments.
HVAC & Plumbing
Convert air and water flow rates between metric and imperial units. Size pumps and fans based on volumetric flow requirements.
Food & Beverage
Measure viscosity of liquids for quality control. Convert flow rates for bottling and packaging lines. Calculate concentration of ingredients.
Key Formulas
- Kinematic Viscosity: ν = μ / ρ (where μ = dynamic viscosity, ρ = density)
- Molarity: M = moles of solute / liters of solution
- Mass Flow Rate: ṁ = ρ × Q (where ρ = density, Q = volumetric flow rate)
- Darcy to m²: 1 D = 9.869233 × 10⁻¹³ m²
- Centipoise to Pa·s: 1 cP = 0.001 Pa·s
Why Use Our Fluids Converter?
- ✅ 98+ Units - Most comprehensive fluids converter available
- ✅ 10 Categories - All major fluid properties covered
- ✅ High Precision - 6 decimal places for accurate calculations
- ✅ Industry Standard - Uses accepted conversion factors
- ✅ Free & Fast - No registration, instant results
- ✅ Mobile Friendly - Works on all devices
- ✅ Professional Grade - Suitable for engineering and scientific work