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Mass Flux Density Converter

Science

Convert mass flux density between kilograms per second-square metre, grams per second-square centimetre, and pounds per hour-square foot instantly.

Reviewed by the thecalcu.com team · Last updated July 16, 2026

From
To
All conversionsfor 1 Pounds per Hour-Square Foot (lb/(hr·ft²))
Kilograms per Second-Square Metre (kg/(s·m²))0.00135623
Grams per Second-Square Centimetre (g/(s·cm²))0.000135623
Pounds per Hour-Square Foot (lb/(hr·ft²))1

What is a Mass Flux Density?

The Mass Flux Density Converter converts mass flux density between kilograms per second-square metre (SI), grams per second-square centimetre (CGS), and pounds per hour-square foot (imperial). Mass flux density measures the rate of mass flow normalised per unit cross-sectional area, a key parameter in pipe flow, membrane filtration, and heat exchanger design.

Enter a value in any supported unit and the converter calculates the equivalent instantly. For the related non-area-normalised quantity, see the Mass Flow Converter.

Why Use a Mass Flux Density Converter?

Membrane filtration specifications, heat exchanger design data, and process engineering references report mass flux density in whatever unit convention matches their industry, SI-based kg/(s·m²) internationally, and imperial lb/(hr·ft²) in US process engineering. Comparing membrane performance or pipe flow data across these unit systems requires accurate conversion.

Who Should Use This Converter?

  • Membrane filtration and separation process engineers comparing membrane flux ratings across manufacturer specifications in different units.
  • Heat exchanger design engineers working with mass flux density data for tube sizing and flow arrangement calculations.
  • Chemical and process engineers converting pipe flow mass flux data across international equipment datasheets.

What Insights Does the Mass Flux Density Converter Give You?

The main output is the converted value in your chosen target unit, calculated precisely from the fixed multiplier relationship between units. Because mass flux density combines both a flow rate and an area normalisation, the converter helps ensure you're comparing genuinely equivalent quantities across different pipe diameters, membrane areas, or unit conventions.

How to use this Mass Flux Density calculator

  1. Choose your starting unit from the source dropdown, for example, "Pounds per Hour-Square Foot".
  2. Enter the numeric value you want to convert in the input field.
  3. Choose your target unit from the destination dropdown, for example, "Kilograms per Second-Square Metre".
  4. Read the converted result, which updates instantly as you type or change units.
  5. Use the swap (⇅) button if you need to reverse the conversion direction.
  6. Use the copy button to grab the result for a membrane design or heat exchanger calculation.
Show formula & methodology ↓Show less ↑

Formula & Methodology

The converter's base unit is kilograms per second-square metre (kg/(s·m²)). Every supported unit has a fixed multiplier:

- 1 gram per second-square centimetre (g/(s·cm²)) = 10 kg/(s·m²)
- 1 pound per hour-square foot (lb/(hr·ft²)) ≈ 0.00135623 kg/(s·m²)

Any conversion follows:

Result = Input × (toBase of source unit ÷ toBase of target unit)

Worked example, converting 100 lb/(hr·ft²) to kg/(s·m²):

Result = 100 × 0.00135623 = 0.1356 kg/(s·m²)

This is the value you'd use directly in an SI-unit membrane or heat exchanger design calculation.

Related Tools

You may also find these useful: Flow Converter.

Frequently Asked Questions

What is mass flux density?
Mass flux density measures the rate of mass flow per unit cross-sectional area, expressed in units like kilograms per second per square metre, it describes how intensely mass is moving through a given area, such as fluid flowing through a pipe cross-section or vapour passing through a membrane.
How does mass flux density differ from mass flow rate?
Mass flow rate (kg/s) measures total mass moving per unit time regardless of area, while mass flux density (kg/(s·m²)) normalises that flow per unit cross-sectional area, two pipes carrying the same mass flow rate but with different diameters will have different mass flux densities. See the [Mass Flow Converter](/mass-flow-converter/) for the non-area-normalised quantity.
How do I convert lb/(hr·ft²) to kg/(s·m²)?
Multiply the lb/(hr·ft²) value by 0.00135623, since one pound per hour-square foot equals approximately 0.00135623 kilograms per second-square metre. Enter your value with 'Pounds per Hour-Square Foot' as the source and 'Kilograms per Second-Square Metre' as the target to apply this automatically.
What applications commonly use mass flux density?
Membrane filtration and separation processes (measuring how much material passes through a membrane per unit area), evaporation and condensation calculations, and pipe flow analysis in process engineering all commonly use mass flux density as a key design parameter.
How is mass flux density related to fluid velocity?
Mass flux density equals fluid density multiplied by velocity (G = ρv), for a given fluid, a higher velocity produces a proportionally higher mass flux density, which is why mass flux is often used in pipe flow and heat exchanger design where velocity effects matter.
What is a typical mass flux density value for membrane filtration?
Membrane filtration flux values vary enormously by membrane type and application, from very low values for reverse osmosis membranes to much higher values for microfiltration, always reference the specific membrane manufacturer's rated flux for a particular application.
Why does the CGS unit g/(s·cm²) appear in some scientific contexts?
CGS-based flux units are still used in some scientific and materials research contexts, particularly in smaller-scale laboratory measurements where the CGS unit's smaller scale produces more convenient numbers than the SI kg/(s·m²) unit.
How does mass flux density relate to heat exchanger design?
Higher mass flux density in a heat exchanger tube generally improves convective heat transfer coefficient (up to a point), which is why heat exchanger designers carefully balance mass flux density against pressure drop when sizing tube diameters and flow arrangements.
Can I use this converter for gas flow through pipes as well as liquid flow?
Yes, mass flux density conversion works identically regardless of the fluid phase, since it's purely a mass-per-time-per-area relationship, applicable to gas, liquid, or two-phase flow calculations.
What's the relationship between mass flux density and molar flux?
Molar flux is the mole-based equivalent of mass flux density, related by the substance's molar mass the same way mass flow and molar flow are related, see the [Molar Flow Converter](/molar-flow-converter/) for the mole-based flow quantity.
Also known as
mass flux density converterkg/s m2 to lb/hr ft2 convertermass flux converterprocess engineering flux convertermembrane flux converter