Inventory Days Calculator
Convert inventory into days of cover at the current rate of sale.
About Inventory Days Calculator
Dividing a balance-sheet stock by the daily flow that passes through it converts money into days. The turns figure is the same relationship inverted: how many times the balance is replaced over the period. Days measures are directly comparable across businesses of any size, and each day removed from the inventory cycle releases cash without needing new financing.
Formula
Inventory Days
Days of Inventory = Average inventory at cost ÷ Annual cost of goods sold × days in period
- Average inventory at cost
- Balance sitting on the balance sheet
- Annual cost of goods sold
- Flow through the income statement over the period
Worked example
With the default values below, Inventory Days Calculator returns Days of Inventory of 60.8. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Average inventory at costminimum 0
- 250,000
- Annual cost of goods soldminimum 0
- 1,500,000
- Days in the periodaccepts 1–366 days
- 365 days
Results
- Days of Inventory
- 60.8 days
- Turns per Period
- 6.00
- Average Daily Flow
- $4,109.59
- Days of Inventory
- 8.69 weeks
- Days of Inventory
- 2.00 months
Step by step
- 1Values used
- 2Inventory Days
- 3Days of Inventory= 60.8 days
- 4Turns per Period= 6.00
- 5Average Daily Flow= 4,109.59
- 6Days of Inventory= 8.69 weeks
- 7Days of Inventory= 2.00 months
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation or tax into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Inventory Days calculated?
Days of Inventory = Average inventory at cost ÷ Annual cost of goods sold × days in period Dividing a balance-sheet stock by the daily flow that passes through it converts money into days. The turns figure is the same relationship inverted: how many times the balance is replaced over the period.
Why does Inventory Days matter?
Days measures are directly comparable across businesses of any size, and each day removed from the inventory cycle releases cash without needing new financing.
What values do I need to enter?
This calculator takes 3 inputs: Average inventory at cost, Annual cost of goods sold, Days in the period. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.