Is this calculator specific to Shopify?

The math is ecommerce-specific and works especially well for Shopify stores because it includes the costs Shopify merchants usually need to model: COGS, payment fees, shipping, returns, ad spend, inventory, conversion rate, or repeat purchases depending on the tool.

Should I use gross margin or contribution margin?

Use contribution margin when you are making advertising, discount, or growth decisions. Gross margin is useful, but contribution margin is stricter because it accounts for variable costs like payment fees, fulfillment, shipping, returns, and app costs.

Why does the tool use default values?

Defaults make the calculator useful immediately and show the shape of the result before you enter your own numbers. Replace them with your store's actual numbers before making a final decision.

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Inventory Aging Calculator

Analyze inventory value by age bucket and estimate aged-stock risk and monthly carrying cost.

Inventory aging calculator

See how much cash is sitting in older stock buckets and what it costs to keep holding that inventory.

0-30 days

31-60 days

61-90 days

90+ days

Annual carrying cost

Aged inventory

$12,000

Total value

$42,000

Aged percent

28.6%

90+ day risk

$5,000

Monthly carry cost

$840.00

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About this tool

What this free tool calculates

Use this to spot when inventory is aging before it becomes dead stock. It is useful for monthly merchandising and finance reviews.

How to use the result

Aged inventory is the value in the 61-90 and 90+ day buckets. Carrying cost is total inventory value times annual carrying cost divided by 12.

Use the 90+ day value as the action list for markdowns, bundles, email campaigns, or purchase-order reductions.

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Why the calculator stays input-driven

This free ecommerce tool does not guess demand, scrape competitors, or invent benchmarks. Change the numbers to match your store, then use the result to decide whether a product, campaign, discount, or inventory move is worth doing.

Frequently Asked Questions

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