Material Weight & Cost Estimator

Estimate raw stock weight (and cost, if you enter a price) for round bar, tube or hex bar in common SYZ materials.

RAW STOCK ESTIMATION · DENSITY × VOLUME

Material Weight & Cost Estimator

Estimates raw stock weight (and cost, if you enter a price) for round bar, tube or hex bar in common SYZ materials.

Stock Shape

Diameter / Across-Flats
[mm]

Bore / Inner Diameter
[mm]

Length
[mm]

Material
Typical Density

Price per kg (optional)
[USD/kg]

Estimated Stock Weight

1,156 g

≈ 2.55 lb

✔
Raw stock weight — does not subtract machined-away material for a finished part.

Engineering Model (geometry × density)

Calculation Method
Round: V=π/4·D²·L · Tube: V=π/4·(Do²−Di²)·L · Hex: V=(√3/2)·AF²·L
Weight = Volume × Density.

Standard Reference
Standard solid-geometry formulas — densities are typical published mill values, not a certified material specification.

Assumptions & Limitations

Estimates raw stock weight (the bar/tube before machining) — a finished machined part will weigh less.
Densities are typical published values; actual mill certs can vary slightly by alloy lot.
Cost estimate (if entered) is raw material cost only — does not include machining, finishing, or scrap allowance.

STATIC REFERENCE DATA

Reference: Density by Material

Precomputed values from the exact formula used above — useful as a quick lookup without re-entering inputs.

WORKED EXAMPLE

A production run needs 25mm round 4130 bar stock, 300mm per part, and material is quoted at $4.50/kg.

Volume = π/4 × 25² × 300 = 147,262 mm³ = 147.26 cm³.
Weight = 147.26 × 7.85 g/cm³ ≈ 1,156 g (2.55 lb) per raw blank.
Material cost per blank ≈ 1.156 kg × $4.50/kg ≈ $5.20 — raw stock only, before machining/scrap allowance.
For a 500-piece run, that’s roughly 578 kg of raw bar and ≈$2,600 in material cost alone — useful for a first-pass BOM estimate before quoting.