Calculate days inventory outstanding.
Please do not make financial decisions based on these results.
What is the DIO Calculator?
Calculate days inventory outstanding. To use the DIO Calculator, enter average inventory, cogs, days in period; it returns dio, inventory turnover, and shows them instantly as you type.
From revenue to cash flow
Work down the income statement: gross margin, operating margin, EBITDA and net margin. Then confirm profit is real cash with the free cash flow calculator and the accrual ratio.
Efficiency ratios show how fast money turns. The Cash Conversion Cycle Calculator combines DSO, DIO and DPO into one number of days.
- Costs. Marginal cost, average variable cost and the optimal price tools support pricing decisions.
- Elasticity. Price, cross-price and income elasticity show how demand reacts.
How to use the DIO Calculator
- Enter your numbers. The inputs are Average inventory ($), COGS ($), Days in period. Use numbers from the same accounting period so the ratios are comparable. Fields marked optional can stay at zero.
- Read the result. The highlighted box gives the DIO, and the cards below show Inventory turnover. Tables and charts break it down further.
- Test other scenarios. Results update as you type. Change one value at a time to see what drives the answer, and press Reset to go back to the defaults.
Formula and how it works
Example with real numbers
Here is the DIO Calculator using the default values shown in the calculator above:
Inputs
| Average inventory ($) | 300,000 |
|---|---|
| COGS ($) | 1,800,000 |
| Days in period | 365 |
Results
| DIO | 60.8 days |
|---|---|
| Inventory turnover | 6× |
With these inputs the calculator returns DIO: 60.8 days. Change any value in the calculator to see how the result moves.
What if you change one input?
Sensitivity check: raising Average inventory ($) from 300,000 to 360,000 (about 20% higher) and leaving everything else as in the example above changes the results like this:
| Result | Example | After the change | Change |
|---|---|---|---|
| DIO | 60.8 days | 73 days | +20% |
| Inventory turnover | 6× | 5× | -16.7% |
The input that moves the result most is the one to check twice. Change it in the calculator above to test your own case.
What the results tell you
The results panel of the DIO Calculator reports DIO and inventory turnover. Compare these figures while changing one input at a time, and use the related calculators below to look at the same situation from another angle.
Method and limits. This calculator applies the formula in the section above to your inputs, in your browser; nothing you enter is stored on our servers. The result is only as accurate as the numbers you enter and the formula shown above. It is for information, not financial, tax or legal advice.
Frequently asked questions
What does a high DIO mean?
Inventory sits for a long time before being sold.
Which accounting standard do the formulas follow?
They use the common textbook definitions that apply under both US GAAP and IFRS unless a tool says otherwise.
Why use average balances?
Ratios that compare a flow (sales, income) with a balance (assets, equity) are fairer when the balance is averaged over the period.
Are the results guaranteed?
No. Results depend entirely on the numbers you enter and the formulas shown on this page. Please do not make financial decisions based on them alone; confirm important figures with a licensed professional.
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