Estimate the weight and cost of a die-cast, gravity and sand-cast aluminum alloys part: pick the alloy grade (density is filled automatically), enter the part volume, and get the weight in kg and lb. Plus a full ASTM ↔ EN ↔ GB ↔ JIS grade cross-reference below.
Tip: get the exact volume from your 3D/CAD model (mass properties).
Estimate only (material + grade). Final cast weight includes gating/risers & machining stock — send your drawing for an exact quote.
Density and minimum properties per ASTM specification. Cross-standard equivalents are by composition/class for reference — confirm exact interchange for critical parts.
| Grade | Density (g/cm³) | Tensile (per ASTM) | Cross-standard equivalent | Typical use |
|---|---|---|---|---|
| A356 (T6) | 2.68 | 234 MPa min (T6) | JIS AC4C / EN AC-42000 AlSi7Mg / GB ZL101 | Structural, leak-tight, heat-treatable |
| A360 | 2.68 | 317 MPa | JIS ADC3 / EN AC-43400 AlSi10Mg / GB YL104 | Die cast, corrosion + strength |
| A380 | 2.74 | 324 MPa | JIS ADC10 / EN AC-46100 / GB YL113 | Most common die-casting alloy |
| A383 | 2.74 | 310 MPa | JIS ADC12 / EN AC-47100 | Thin-wall, intricate die castings |
| A413 | 2.66 | 290 MPa | JIS ADC1 / EN AC-44300 AlSi12 / GB YL102 | Pressure-tight, complex shapes |
| ADC12 | 2.7 | ≈ A383 (310 MPa) | JIS H5302 / EN AC-47100 | JIS-standard die casting (≈ A383) |
Casting weight = part volume × material density. Get the volume from your 3D/CAD model, select the alloy for its density (aluminum casting grades shown above), multiply to get grams, then divide by 1000 for kilograms. Add gating, risers and machining allowance for the as-cast weight.
Not exactly. A380 is closest to JIS ADC10, while A383 corresponds to JIS ADC12. A383/ADC12 has slightly higher silicon and lower copper than A380, giving better fluidity for thin walls. They are often substituted but differ in composition — confirm the spec for your application.
With aluminum castings, weight is rarely just a shipping number — it is the whole reason the part exists. Lightweighting is the core value proposition of cast aluminum: at roughly 2.70 g/cm³, aluminum is about one third the weight of iron or steel (around 7.1–7.85 g/cm³). Knowing the cast weight early lets you validate that switch from a ferrous part before you commit to tooling, and it is the single biggest lever on material cost, freight, and how the part behaves in the final assembly.
The math itself is simple and transparent: weight (kg) = part volume (cm³) × alloy density (g/cm³) ÷ 1000. The volume comes from your CAD model's mass-properties readout; the density comes from the alloy you choose. Among common cast aluminum alloys the density only shifts a little — LM6/AlSi12 at 2.65, A356 at 2.68, A380 at 2.71, ADC12/A383 at 2.74 — so swapping grades barely moves the scale. What the alloy choice really changes is cost, castability, and mechanical properties: gravity-cast A356 for leak-tight, heat-treatable structural parts versus high-volume die-cast ADC12 for thin, intricate housings. Use this calculator to lock in the weight target, then choose the alloy on properties and process — not on the small density difference. For background on the alloys and processes, see our aluminum casting overview.
A solid rectangular bracket measuring 250 × 120 × 30 mm has a bounding volume of 250 × 120 × 30 = 900,000 mm³, which is 900 cm³ (divide by 1000). Casting it in A356 / AlSi7Mg at a density of 2.68 g/cm³:
900 cm³ × 2.68 g/cm³ ÷ 1000 = 2.41 kg
That 2.41 kg is the net part weight. The as-cast weight from the foundry will be higher once gating, risers, and machining stock are added — see the trust note below.
To show why teams move to aluminum, take the identical 900 cm³ geometry and cast it in iron at 7.15 g/cm³ instead:
900 cm³ × 7.15 g/cm³ ÷ 1000 = 6.43 kg
Same shape, but the iron version weighs 6.43 kg versus 2.41 kg in A356 — a saving of about 4.0 kg, roughly 63% lighter. On a vehicle, robot arm, or anything that has to move or be carried, that mass reduction is exactly what justifies the cost of an aluminum casting and its tooling.
Real castings are rarely solid blocks. Take a die-cast housing with outer dimensions 180 × 100 × 60 mm and an internal cored cavity of 140 × 70 × 40 mm. Work out the net volume by subtracting the void:
Outer: 180 × 100 × 60 = 1080 cm³
Cavity: 140 × 70 × 40 = 392 cm³
Net volume: 1080 − 392 = 688 cm³
In ADC12 / A383 at 2.74 g/cm³:
688 cm³ × 2.74 g/cm³ ÷ 1000 = 1.89 kg
If you forgot the cored cavity and treated the part as solid (1080 cm³) you would get 2.96 kg — over 50% too heavy. Always use the true net volume from your CAD mass properties, which already accounts for cores, fillets, and draft.
| Alloy / grade | Density (g/cm³) | Typical process & use |
|---|---|---|
| A356 / AlSi7Mg | 2.68 | Gravity die and sand casting; heat-treatable (T6), leak-tight structural parts, wheels and chassis brackets |
| A380 | 2.71 | High-pressure die casting; the most common general-purpose die alloy, good strength and castability |
| ADC12 / A383 | 2.74 | High-pressure die casting; excellent fluidity for thin walls and intricate housings (A383 is the ASTM near-equivalent of JIS ADC12) |
| LM6 / AlSi12 | 2.65 | Sand and gravity casting; near-eutectic, very fluid and pressure-tight, good for complex or marine parts |
| 6061 | 2.70 | Wrought alloy shown for comparison/machining reference; not a casting alloy but common in machined-from-billet and hybrid parts |
| Generic aluminum | ~2.70 | Use as a default when the exact cast alloy is not yet decided |
Densities are nominal room-temperature values for the alloy. Actual part density varies slightly with porosity, heat-treat temper, and exact chemistry within the spec. For comparison, gray/ductile iron sits near 7.1–7.3 g/cm³ and steel near 7.85 — about three times heavier than aluminum.
Estimating cast aluminum weight early matters across every industry where mass, cost, or assembly fit is on the line. In automotive and EV work, every kilogram removed from a bracket, housing, or battery component improves range and handling, so weight targets are set before the alloy is even chosen. Electronics and telecom teams weigh die-cast enclosures and heat-sink housings to balance thermal mass against shipping cost; lighting and consumer-product designers do the same for fixtures and bodies where feel and freight both count. Aerospace component engineers treat weight as a hard requirement, and pump and fluid-power makers use it to size castings against pressure-tight, leak-free targets. Across all of these, design engineers validate concepts, sourcing teams compare quotes on a per-kilogram basis, and product developers sanity-check whether a part can realistically hit its weight goal in aluminum.
This calculator is deliberately transparent: it applies the universal formula weight = volume × density ÷ 1000 using published nominal densities for standard cast aluminum alloys. There is no hidden fudge factor — if you know your part's true volume, the net-part weight it returns is as accurate as that volume figure. It is, however, an indicative estimate, and the real as-cast and finished weight can differ for a few honest reasons:
For a weight and price tied to your actual drawing and process, send us your part for a quote rather than relying on the estimate alone.
About two-thirds lighter. Aluminum casting alloys average around 2.70 g/cm³ versus roughly 7.1–7.3 g/cm³ for iron and 7.85 for steel, so an identical geometry in aluminum weighs about one third as much — a saving of roughly 60–65%. For example, a 900 cm³ bracket is 2.41 kg in A356 but 6.43 kg in cast iron.
Barely. Common cast aluminum alloys range only from about 2.65 g/cm³ (LM6/AlSi12) to 2.74 g/cm³ (ADC12/A383) — under a 4% spread — so swapping grades changes the weight by a few percent at most. Pick the alloy on castability, strength and process (die, gravity or sand) rather than on density, then use its value here for a precise estimate.
This tool gives the net weight of the finished part geometry. The as-cast weight also includes the gating, runners and risers used to fill the mold, plus any machining allowance left for finishing. Those are trimmed or machined off afterward, but they mean the metal actually poured — and what some quotes are based on — is more than the net part weight.