How do you calculate foundry scrap cost?

Multiply the number of scrapped castings by the fully loaded cost per scrapped unit, apply the scrap cost allocation percentage, then add any fixed containment or disposal cost. With 22 scrapped parts at $145 each, 100% allocation, plus $800 disposal, total scrap cost is $3,990.

What should the cost per scrapped unit include?

It should reflect everything sunk into the part before it was condemned: melt and remelt energy, alloy and return loss, core and mold materials, pouring labor, and any machining done before final inspection. Using only the metal sale-back value badly understates the loss.

What is scrap cost per rejected unit and why does it differ from the input cost?

It is total cost divided by the number of rejects. In the example it is $181.36 per piece, higher than the $145 input because the $800 fixed containment cost is spread across the 22 rejected parts.

What is a good foundry scrap rate?

Internal scrap of 3-5% of good castings is common in jobbing iron and aluminum foundries; high-volume automotive lines run well under 2%. Pair this calculator with a piece-count rate to convert defect percentage into dollars.

Scrap cost vs cost of poor quality — what's the difference?

Scrap cost is the direct loss from condemned parts. Cost of poor quality is broader: it adds rework, sorting, warranty, and lost throughput. This calculator gives you the scrap component, which is usually the largest single line in a foundry COPQ report.

How does the allocation percentage work?

It lets you assign only part of the unit cost to a cost center or project — for example 50% if metal is recovered and remelted. At 100% allocation the full per-unit cost applies, giving the $3,190 variable scrap cost in the worked example.

Foundry & Forging calculator

Foundry Scrap Cost Calculator

Foundry scrap cost captures the real money lost when castings or forgings are rejected at shakeout, inspection, or machining — not just the metal weight, but the melt energy, labor, and binder already poured into a part that ends up in the return bin. Foundry managers, quality engineers, and cost accountants use it to put a defensible dollar figure on internal rejects so reduction projects can be prioritized against actual loss. It matters because a single hidden-shrinkage or gas-porosity problem can quietly consume more margin than a whole shift's labor. This calculator separates the variable per-unit loss from fixed containment and disposal charges so you see both the recurring drain and the one-time cleanup cost.

What this calculator does

Estimate the cost impact of scrap castings, rejected forgings, failed molds, bad cores, or nonconforming heat lots.
Use it when scrap affects quote margin, production cost, root-cause priority, or customer recovery for a casting or forging program.
It computes total foundry scrap cost (variable reject cost plus a fixed containment or disposal charge) and the average scrap cost per rejected unit.

Formula used

Total foundry scrap cost = scrapped castings or forgings × cost per scrapped unit × scrap cost allocation + fixed containment or disposal cost
Scrap cost per rejected unit = total cost ÷ scrapped castings or forgings

Inputs explained

Scrapped castings or forgings:
Cost per scrapped unit:
Scrap cost allocation:
Fixed containment or disposal cost:

How to use the result

Use it when reviewing a defect spike, building a cost-of-poor-quality report, or justifying a corrective-action project on a specific part number or alloy.
The cost per scrapped unit you enter is only as good as your fully loaded estimate — if it omits melt energy, core sand, or downstream machining already invested in the part, total scrap cost will be understated.

Current U.S. benchmarks

The producer price index for steel mill products stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 3,569 primary metal manufacturing establishments employing about 354,911 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate foundry scrap cost? Multiply the number of scrapped castings by the fully loaded cost per scrapped unit, apply the scrap cost allocation percentage, then add any fixed containment or disposal cost. With 22 scrapped parts at $145 each, 100% allocation, plus $800 disposal, total scrap cost is $3,990.
What should the cost per scrapped unit include? It should reflect everything sunk into the part before it was condemned: melt and remelt energy, alloy and return loss, core and mold materials, pouring labor, and any machining done before final inspection. Using only the metal sale-back value badly understates the loss.
What is scrap cost per rejected unit and why does it differ from the input cost? It is total cost divided by the number of rejects. In the example it is $181.36 per piece, higher than the $145 input because the $800 fixed containment cost is spread across the 22 rejected parts.
What is a good foundry scrap rate? Internal scrap of 3-5% of good castings is common in jobbing iron and aluminum foundries; high-volume automotive lines run well under 2%. Pair this calculator with a piece-count rate to convert defect percentage into dollars.
Scrap cost vs cost of poor quality — what's the difference? Scrap cost is the direct loss from condemned parts. Cost of poor quality is broader: it adds rework, sorting, warranty, and lost throughput. This calculator gives you the scrap component, which is usually the largest single line in a foundry COPQ report.

Last reviewed 2026-05-12.