Free · Microeconomics calculators 💲

Inventory Cost & Holding Days Calculator

Estimate inventory days from average stock value and cost of goods sold.

  • Formula & worked example
  • Private in your browser
  • No signup
Go to tool

Calculator inputs

Loading calculator…

How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Edit a calculated value to solve backwards, or lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

Use the result with context

Results are estimates for planning and education. Confirm rates, taxes, fees, and legal requirements with the relevant institution or a qualified professional before making a financial decision.

Formula and method

Opening inventory of 10,000 and closing inventory of 20,000 average 15,000. Cost of goods sold of 90,000 across 360 days gives 60 inventory days.

Inventory days = average inventory at cost ÷ cost of goods sold × period days

Worked example

Enter these known values and leave the other values blank.

Starting inventory
10000 USD
Ending inventory
20000 USD
Cost of goods sold (COGS)
90000 USD
Days in accounting period
360 days
Average inventory
15000 USD
DIO
60 days

Assumptions and limitations

  • Use inventory cost consistently with cost of goods sold. A beginning-and-ending average can hide seasonal stocking changes, and the result is an aggregate estimate rather than an individual item’s age.
  • Use consistent periods, currency and accounting definitions. The result follows the stated formula and the figures you supply.

Common questions

Can I use selling prices for the inventory balance?

Use inventory cost consistently with cost of goods sold. A beginning-and-ending average can hide seasonal stocking changes, and the result is an aggregate estimate rather than an individual item’s age.

References

The calculation equations, inverse formulas, units, and input rules were imported from this source. Bookify provides the interface and equation solver.

Explore microeconomics calculators 💲 or browse all finance calculators.