How do you calculate network inventory impact?

Multiply average units held by the annual carrying cost per unit and by the design-added share, then add the write-off buffer. Here that's 65,000 x $9.50 x 40% + $55,000 = $302,000 per year.

What does the design-added share mean?

It's the fraction of the inventory cost the change is actually responsible for. If a network change drives 40% of the on-hand stock, you charge 40% of the carrying cost to that decision, not all of it.

What's a typical annual carrying cost per unit?

Carrying cost usually runs 20-30% of unit value per year covering capital, storage, insurance, and shrink. The $9.50/unit here reflects a unit worth roughly $35-45 at a 22-25% carrying rate.

Why add an expedite and obsolescence buffer?

Longer or more complex networks generate one-off costs — air freight to recover from delays and write-offs of stranded stock — that aren't captured by steady-state carrying cost. The buffer makes the estimate honest.

What is the cost per unit telling me?

It spreads the total impact across average units held. At $302,000 over 65,000 units that's $4.65 per unit, a clean figure to drop into a per-piece landed-cost comparison.

How is variable cost different from the fixed adder?

The variable piece ($247,000) scales with volume and carrying rate; the fixed adder ($55,000) is the buffer that holds regardless of how many units you carry.

Make-Buy, Outsourcing & Network Design calculator

Network Inventory Impact Calculator

Network Inventory Impact estimates the annual dollar cost that a network design change or sourcing decision adds to inventory you have to carry. It takes the average units held across your network, multiplies by the annual carrying cost per unit and the share of that inventory the change is responsible for, then adds a buffer for expedite and obsolescence write-offs. Supply-chain and operations leaders use it to put a real number on the working-capital penalty of moving production, adding a distribution node, or lengthening a supply lane. It's the inventory line item that make-vs-buy business cases routinely forget.

What this calculator does

Estimates the annual inventory cost impact of a network design from incremental carrying cost plus expedite and obsolescence exposure.
Use it when a make-buy or footprint change shifts where stock sits and you need to price the resulting inventory burden.
It computes the annual carrying cost attributable to a design or network change plus a fixed expedite-and-obsolescence buffer.

Formula used

Inventory impact = average units x carrying cost x design-added share + write-off buffer
Carrying impact per unit held = inventory impact / average units

Inputs explained

Average inventory units held in network:
Annual carrying cost per unit:
Share of inventory added by the design change:
Expedite and obsolescence write-off buffer:

How to use the result

Use it when evaluating a network redesign, an offshore-to-nearshore move, or any decision that changes how much inventory the network must hold.
It uses an average inventory level and a flat carrying rate, so it won't capture seasonal swings or the way carrying cost rises non-linearly as obsolescence risk climbs.

Current U.S. benchmarks

Sourcing currencies as of 2026-07-02 (Federal Reserve H.10): 6.7886 CNY and 17.4524 MXN per USD. Landed-cost comparisons move with these daily rates.
U.S. iron and steel imports ran $2.1B in May 2026 (Census International Trade). The U.S. ran a trade deficit of $0.4B in the category that month. Import volumes are the pressure gauge behind tariff and reshoring decisions.

Common questions

How do you calculate network inventory impact? Multiply average units held by the annual carrying cost per unit and by the design-added share, then add the write-off buffer. Here that's 65,000 x $9.50 x 40% + $55,000 = $302,000 per year.
What does the design-added share mean? It's the fraction of the inventory cost the change is actually responsible for. If a network change drives 40% of the on-hand stock, you charge 40% of the carrying cost to that decision, not all of it.
What's a typical annual carrying cost per unit? Carrying cost usually runs 20-30% of unit value per year covering capital, storage, insurance, and shrink. The $9.50/unit here reflects a unit worth roughly $35-45 at a 22-25% carrying rate.
Why add an expedite and obsolescence buffer? Longer or more complex networks generate one-off costs — air freight to recover from delays and write-offs of stranded stock — that aren't captured by steady-state carrying cost. The buffer makes the estimate honest.
What is the cost per unit telling me? It spreads the total impact across average units held. At $302,000 over 65,000 units that's $4.65 per unit, a clean figure to drop into a per-piece landed-cost comparison.

Last reviewed 2026-05-12.