Foundry & Forging calculator

Melt Loss Calculator

Melt loss is the metal that disappears between weigh-out and tapped, usable iron or aluminum — burned off as oxide dross, slag, splash, and skull. Foundry metallurgists and cost estimators track it because at $1.85/lb scrap and hundreds of pounds lost per heat, oxidation losses quietly erode margin on every casting poured. This calculator converts pounds of melt loss into real dollars and a per-pound cost so you can compare furnace practices, fluxes, and charge materials. It is the number that tells you whether your 3% loss on a gray iron heat is normal or bleeding cash.

What this calculator does

  • Estimate the cost of melt loss from oxidation, slag, dross, furnace hold loss, ladle loss, returns, and alloy trim waste.
  • Use it when quoting castings, reviewing heat performance, or deciding whether melt practice, furnace lining, charge mix, or ladle handling is costing too much metal.
  • It multiplies pounds of metal lost by charge price and the unrecoverable share, then adds fixed melt handling cost to give total melt loss dollars and cost per pound lost.

Formula used

  • Total melt loss calculator = melt loss weight × metal cost per weight unit × recoverable loss included + fixed melt handling cost
  • Melt loss cost per weight unit = total cost ÷ melt loss weight

Inputs explained

  • Metal lost per melt cycle:
  • Charge metal price per pound:
  • Share of loss treated as unrecoverable:
  • Fixed furnace and flux handling cost:

How to use the result

  • Use it when costing a melt practice, comparing alloys or chargers, or building a per-pound surcharge into a casting quote.
  • It treats price and loss rate as flat averages; actual oxidation loss varies heat-to-heat with charge cleanliness, holding time, and turbulence, so use representative figures, not best-case ones.

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 melt loss cost? Multiply pounds lost by metal price per pound and the unrecoverable percentage, then add fixed handling cost. With 380 lb lost at $1.85/lb, 100% unrecoverable, plus $120 handling, total melt loss is $823.
  • What is a typical melt loss percentage in a foundry? Clean gray iron in an induction furnace often runs 1-3%, dirty or oily steel scrap can exceed 5-7%, and aluminum melt loss frequently lands at 3-8% because of its high oxide affinity. Compare your figure against the alloy and furnace type, not a single benchmark.
  • What does cost per pound lost tell me? It spreads the full melt loss dollars across the pounds lost. In the worked example, $823 over 380 lb is $2.17/lb — higher than the $1.85 metal price because the fixed $120 handling cost rides on top of every lost pound.
  • Melt loss vs. yield loss — what's the difference? Melt loss is metal vaporized or oxidized during melting and holding. Yield loss is good metal locked in gates, risers, and runners that gets returned and remelted. Melt loss is gone for good; yield loss is recoverable but recirculates as melt-loss-prone return.
  • How do I reduce melt loss? Charge clean, dry, dense scrap; minimize superheat and holding time; reduce stirring turbulence; cover aluminum melts with flux; and keep slag and dross worked off promptly. Each lever drops oxidation, and at $2.17/lb every point counts.

Last reviewed 2026-05-12.