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Inventory Days on Hand Calculator

Days of cover at current stock and current demand.

Written and maintained by Mohit PatelLast checked August 4, 2026How we build these
units
days

Days on hand

40 days

clears your lead time

Weeks of cover5.7 weeks
Supplier lead time21 days
Days of headroom19 days
Order byday 19

How the Inventory Days on Hand Calculator works

Days on hand answers the operational question rather than the accounting one: at today's rate of sale, how long until this runs out? Compared against lead time it tells you immediately whether an order is overdue.

Not financial advice. Marketplace fees change, and they vary by country, plan and seller status. Every rate here is an editable default, not a quoted price — check the platform's current fee schedule before you price a product against it. This is not tax or business advice.

Frequently asked questions

How is days on hand calculated?

Current stock ÷ average daily unit sales. 480 units selling 12 a day is 40 days on hand. Unlike DSI, this uses current stock rather than an average, which makes it useful for a decision today.

How does it compare to lead time?

That comparison is the whole point. Days on hand below lead time means you will stock out before a replacement order can arrive, regardless of what you do now. That is the moment to expedite or accept the gap.

Should I use recent or annual average demand?

Recent, weighted toward the last few weeks, and adjusted for anything you know is coming. An annual average will badly mislead you going into a seasonal peak, which is exactly when the number matters most.

What is a healthy days on hand?

Roughly lead time plus a safety buffer plus half your order cycle. If lead time is 21 days and you order monthly, something in the region of 45-60 days is comfortable. Much beyond that is cash sitting still.

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