How do you calculate good surchargeable tons?

Multiply tons per cycle by cycles for gross output, then multiply by uptime and first-pass yield. For 20 tons × 40 cycles = 800 gross, × 90% uptime × 97% yield = 698.4 good surchargeable tons.

Why not surcharge gross tonnage?

Because downtime and off-spec losses mean you can't sell every gross ton. Billing surcharge on 800 gross tons when only 698.4 ship overstates the charge by the 80 tons lost to downtime and 21.6 tons lost to yield.

What's the difference between downtime loss and yield loss here?

Downtime loss is metal never produced because the line wasn't running — 80 tons in the example. Yield loss is metal produced but rejected on first pass — 21.6 tons. They apply in sequence, so yield loss is taken on post-downtime tonnage.

What is a good first-pass yield for a mill?

First-pass yields above 95% are strong for most rolled and processed products; the 97% in the example is excellent. Lower-yield grades or new products may run 88-93% and pull surchargeable tonnage down noticeably.

Does rework change surchargeable tons?

It can — this calculator counts only first-pass good tons, so metal recovered through rework would add back tonnage. Treat the result as a conservative, first-pass base for surcharge planning.

How does uptime affect surcharge revenue?

Linearly on the volume base. Dropping uptime from 90% to 80% would cut gross-to-good by another 80 tons in this example, directly shrinking the tonnage every surcharge rate is applied to.

Metals, Steel, Aluminum & Coil Processing calculator

Metal Surcharge Impact Calculator

Good surchargeable tons is the volume of saleable, on-spec metal a period will actually produce — the base on which alloy and energy surcharges are correctly billed. Mill schedulers, commercial teams, and metallurgists use it because surcharges applied to gross or nameplate tonnage overstate revenue and customer charges, while applying them to realized good tons keeps invoices defensible. Gross output is discounted by both downtime and first-pass yield, since metal that wasn't made or didn't pass spec can't carry a surcharge. This calculator chains those two losses onto your per-cycle output to give the good tonnage you should actually surcharge against.

What this calculator does

Estimate the good tonnage a metal surcharge will apply to by combining output per production cycle, the cycles available, uptime, and first-pass yield.
Use it when a buyer or estimator needs the real surchargeable tonnage per period before pricing a metal surcharge into a contract.
It computes good surchargeable tons as gross output (tons per cycle × cycles) reduced by expected uptime and first-pass yield, and shows the downtime and yield losses separately.

Formula used

Gross output tons = output per cycle × production cycles
Good surchargeable tons = gross output tons × expected uptime × first-pass yield

Inputs explained

Tons produced per cycle:
Production cycles in the period:
Expected uptime:
First-pass yield:

How to use the result

Use it when forecasting surcharge-bearing volume for a period or reconciling billed surcharge tonnage against realized good output.
It applies uptime and yield as flat period averages — it doesn't model grade-specific yield, rework that recovers tonnage, or surcharge rate differences across alloys, so it sizes volume, not dollars.

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 producer price index for aluminum mill shapes stands at 404.859 (BLS, May 2026), up 36.8% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).

Common questions

How do you calculate good surchargeable tons? Multiply tons per cycle by cycles for gross output, then multiply by uptime and first-pass yield. For 20 tons × 40 cycles = 800 gross, × 90% uptime × 97% yield = 698.4 good surchargeable tons.
Why not surcharge gross tonnage? Because downtime and off-spec losses mean you can't sell every gross ton. Billing surcharge on 800 gross tons when only 698.4 ship overstates the charge by the 80 tons lost to downtime and 21.6 tons lost to yield.
What's the difference between downtime loss and yield loss here? Downtime loss is metal never produced because the line wasn't running — 80 tons in the example. Yield loss is metal produced but rejected on first pass — 21.6 tons. They apply in sequence, so yield loss is taken on post-downtime tonnage.
What is a good first-pass yield for a mill? First-pass yields above 95% are strong for most rolled and processed products; the 97% in the example is excellent. Lower-yield grades or new products may run 88-93% and pull surchargeable tonnage down noticeably.
Does rework change surchargeable tons? It can — this calculator counts only first-pass good tons, so metal recovered through rework would add back tonnage. Treat the result as a conservative, first-pass base for surcharge planning.

Last reviewed 2026-05-12.