Compressed mesh parts
Document the finished dimensions, net mass and agreed compression condition for compressed knitted filters.
Engineering tool · Shaped knitted mesh
Knitted Mesh Density & Porosity Calculator
Calculate bulk density and theoretical void fraction from dry net mesh mass and finished dimensions, or find the net mesh mass required for a specified density or porosity.
Use project-specific measurements. This mass-and-volume calculation does not select a packing grade or publish a standard density for knitted mesh products. Defaults are illustrative arithmetic inputs.
Enter the mesh body
Use consistent dimensions, net mass and solid wire density.
Mass and volume results
Volumetric estimates for the entered envelope and material.
Mesh envelope volume—
Bulk density—
Theoretical porosity—
Net mesh mass—
Solid material volume—
Estimated void volume—
Calculation basis
ρbulk = mnet/V; ε = 1 − ρbulk/ρsolid
Target mass: m = ρbulk,targetV = (1 − εtarget)ρsolidV
Block: V = LWH; disc: V = πD²H/4; ring: V = π(D² − d²)H/4.
Internal units: m, kg, m³ and kg/m³. Porosity is a volume fraction, not projected open area.
Use the result with the right product data
Demister pads
For demister pads, exclude support grids. This tool calculates geometry, not vapour capacity or droplet removal.
Woven sheet weight
Use the woven wire mesh weight calculator for regular woven mesh. Knit loops are not a square mesh-count geometry.
Worked example
An illustrative rectangular mesh envelope of 100 × 100 × 50 mm has a volume of 0.0005 m³. With dry net mesh mass 0.2 kg and solid material density 8,000 kg/m³, bulk density is 400 kg/m³ and theoretical porosity is 95%. Solid volume is 25 cm³ and estimated void volume is 475 cm³.
The same geometry needs 0.2 kg of net mesh for a target bulk density of 400 kg/m³ or a target porosity of 95% with this entered solid density. These values are not a product recommendation.
Frequently asked questions
What is the difference between bulk density and material density?
Bulk density is dry net mesh mass divided by the shaped mesh envelope volume, including its voids. Solid material density describes the wire material itself. They are different inputs and cannot be interchanged.
Should the support frame be included in the mass?
No. Use dry net mesh mass only. Subtract known frame, grid, housing and support masses before entering the value. Liquid, dirt and retained process material also affect the result.
Which dimensions should I measure?
Use the actual shaped or installed mesh envelope at an agreed measurement condition. Exclude the central opening of an annular part. Compression changes volume and therefore bulk density; record the measurement condition with the result.
Does this determine pore size or filtration efficiency?
No. Mass-based void fraction is a volumetric geometric estimate. It does not measure connected flow paths, pore-size distribution, pressure drop, separation efficiency, resilience or fatigue performance.
Can I use it for co-knitted or mixed-material products?
The formula assumes one material with a known solid density. Mixed materials, coatings and composite fibres require a separately verified equivalent solid density or component-by-component solid-volume calculation. Do not substitute a single-alloy density without verification.
Are the sample values recommended product specifications?
No. All defaults are arithmetic examples. Enter project-specific dimensions, net mass and solid density. Target density or porosity must come from the agreed drawing or specification; the calculator does not select them.
Formula references
Fluids: experimental mesh voidage from mass and volume · NIST: unit conversion factors. Target-mass modes rearrange the same mass balance.
Review your formed mesh specifications
Share the material, drawing, finished dimensions, measurement condition and agreed density requirements.
Discuss your specificationsFor dry, single-material shaped knitted mesh with simple envelopes. Excludes irregular cutouts, unverified composite densities and product performance prediction. Density, porosity and acceptance conditions require project-specific agreement.
