How do you calculate coil storage cost?

Multiply coil-months by the rate and billable share, then add fixed handling. For 120 coil-months at $8 each, fully billable, plus $200 handling, that is 120 x 8 x 100% + 200 = $1,160 total.

What is a coil-month?

It is one coil stored for one month — the standard unit for inventory carrying. Twelve coils held for ten months, or 120 coils held for one month, both equal 120 coil-months.

What does billable share mean?

It is the percentage of stored coil-months you actually charge for, after free-storage windows or consignment terms. At 100% everything is billed; drop it to 80% and the variable cost falls proportionally while fixed handling stays the same.

Why is the cost per coil-month higher than the storage rate?

Because the fixed handling cost spreads across the coil-months. In the example the $8 rate becomes about $9.67 per coil-month once the $200 handling is averaged over 120 coil-months.

What is a good coil storage cost?

Lower is better, but the real question is whether carrying cost is eroding your margin on the metal. If holding coil costs more per month than your expected price gain from waiting, you are storing too long.

Should I bill fixed handling separately?

Many service centers do, because crane and forklift moves happen on receipt and shipment regardless of dwell time. Keeping it separate from the per-coil-month rent makes invoices easier to defend.

Metals, Steel, Aluminum & Coil Processing calculator

Coil Storage Cost Calculator

Coil storage cost is the carrying expense of holding steel or aluminum coil inventory, built from how long each coil sits, the warehouse rate, and the fixed handling that comes with moving heavy coils in and out. Inventory managers, service-center controllers, and toll-storage operators use it to bill customers fairly, price warehousing contracts, and decide when slow-moving stock should be sold down. Coil ties up both floor space and capital, so a clear monthly cost makes the case for tighter turns. This calculator splits the variable rental from the fixed handling so each lever is visible.

What this calculator does

Estimate coil storage cost from coil-months stored, the storage rate per coil-month, the billable share, and a fixed handling cost.
Use it when a service center manager prices warehouse or toll storage and needs the carrying cost of coils held over time.
It multiplies coil-months by the storage rate and billable share for the variable cost, then adds fixed handling to give a total storage cost.

Formula used

Variable storage cost = coil-months stored × storage rate × billable share
Total storage cost = variable storage cost + fixed handling cost

Inputs explained

Coil-months in storage:
Warehouse rate per coil-month:
Billable share of inventory:
Fixed handling and crane cost:

How to use the result

Use it to invoice toll-storage customers, to model inventory carrying cost, or to justify reducing on-hand coil.
It uses one flat storage rate; tiered pricing, demurrage after a free period, or climate-controlled premiums need separate handling.

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 coil storage cost? Multiply coil-months by the rate and billable share, then add fixed handling. For 120 coil-months at $8 each, fully billable, plus $200 handling, that is 120 x 8 x 100% + 200 = $1,160 total.
What is a coil-month? It is one coil stored for one month — the standard unit for inventory carrying. Twelve coils held for ten months, or 120 coils held for one month, both equal 120 coil-months.
What does billable share mean? It is the percentage of stored coil-months you actually charge for, after free-storage windows or consignment terms. At 100% everything is billed; drop it to 80% and the variable cost falls proportionally while fixed handling stays the same.
Why is the cost per coil-month higher than the storage rate? Because the fixed handling cost spreads across the coil-months. In the example the $8 rate becomes about $9.67 per coil-month once the $200 handling is averaged over 120 coil-months.
What is a good coil storage cost? Lower is better, but the real question is whether carrying cost is eroding your margin on the metal. If holding coil costs more per month than your expected price gain from waiting, you are storing too long.

Last reviewed 2026-05-12.