How to Calculate Casting Cost per Kg: A Practical Foundry Guide

What is metal casting cost?

Metal casting cost is the total cost of making a casting that meets the customer's specification. Depending on the process and the level of costing you need, it includes:

• Raw metal and alloying materials
• Melting and pouring energy
• Moulding sand, binders, cores and other consumables
• Direct labour
• Pattern and tooling cost
• Fettling, finishing and machining
• Inspection and testing
• Rejection, rework and material losses
• Maintenance and factory overheads

The exact structure depends on the material, the component design, volumes, the process route and customer requirements.

What is the casting cost per kg formula?

Use saleable weight because rejected castings also consume metal, energy, labour and consumables. If 1,000 kg is produced and only 950 kg passes inspection, divide the total cost by 950 kg, not 1,000 kg. Dividing by the melted or poured weight makes every casting look cheaper than it is.

What are the six components of casting cost?

1. Raw material cost

Take the metal actually consumed, including process losses, and subtract the value of returns you can re-melt, such as runners, risers and rejected castings.

Use actual consumption and recovery data, not standard figures. Casting yield drives this number; see how to calculate casting yield.

2. Melting and energy cost

Electricity or fuel used for melting and holding. Track it heat by heat or batch by batch so you can see energy per kg of metal melted.

3. Moulding and consumables

Moulding sand, core sand, binders, refractories, coatings and finishing consumables.

4. Labour and processing

Mould preparation, pouring, fettling, finishing, machining and inspection.

5. Rejection and rework

Rejected castings and rework add cost without adding saleable output.

Track rejection by component, heat, defect and stage. Our defect-wise rejection analysis guide shows how.

6. Overheads and tooling

Depreciation, maintenance, indirect labour, utilities, quality-control expenses and pattern or die costs, allocated to the castings that use them.

Worked example: casting cost per kg for one batch

Illustrative figures only. They are not industry benchmarks or recommended rates.

The batch produces 800 kg of saleable castings.

If the selling price is ₹300 per kg, the difference is ₹50 per kg before selling, administration and finance costs, so do not treat it as net profit.

In this example metal is 60% of the cost, which is why charge-mix choices and yield move cost per kg more than anything else.

How can a foundry make casting costing more accurate?

Accurate costing needs reliable production and consumption data. Review these every month:

• Metal consumption and material recovery
• Energy cost per kg of metal melted
• Casting yield and rejection rates
• Labour and machine utilisation
• Actual cost against estimated cost, per component

How does foundry ERP keep item-wise costing accurate?

When costing lives in spreadsheets, actual costs from each stage arrive late, and some never arrive. A foundry ERP captures consumption, energy, labour and rejection where they happen, so cost per kg is calculated from actual data for every heat and every item.

ICAST's item-wise costing and profitability report shows the real cost and margin of every item you cast, so you can find loss-making castings and quote from actual cost. It is part of ICAST Pro and can be added to ICAST Lite as a module. Combined with Meltix least-cost charge mix, which customers have measured at up to 4% lower charge cost for iron, 6% for aluminium and copper alloys and 8% for steel, it attacks the biggest line in the table above.