Inventory Cover Days Calculator
Inventory cover translates a stock quantity and demand rate into an approximate number of days of supply.
How to use this calculator
- Enter stock available for use and average demand per day in matching units.
- Check that every input uses the stated units and covers the same period, population or project scope.
- Change one assumption at a time when comparing scenarios.
Formula used by inventory cover days calculator
Days of cover = usable stock ÷ average daily demand
- Days of cover = usable stock ÷ average daily demand
- It does not model lead-time variation, safety stock, seasonality, damaged inventory, orders in transit or changing demand.
- Inputs are validated against the tool-specific constraints; displayed results are rounded for readability.
Worked examples
Worked example
840 usable units at an average demand of 35 units per day provide 24 days of cover.
The calculation divides usable stock by the stated average daily demand.
The calculation divides usable stock by the stated average daily demand.
Understanding the result
Inventory cover translates a stock quantity and demand rate into an approximate number of days of supply.
It does not model lead-time variation, safety stock, seasonality, damaged inventory, orders in transit or changing demand.
Important notes
It does not model lead-time variation, safety stock, seasonality, damaged inventory, orders in transit or changing demand.
Treat the result as an estimate for the assumptions entered; verify important specifications against the relevant source or professional guidance.
Frequently asked questions
Does inventory cover replace reorder planning?
No. Reorder decisions also depend on lead time, service targets, safety stock and incoming stock.
Should unusable stock be included?
Exclude damaged, reserved or otherwise unavailable units from the usable stock input.
How should I use this result?
Enter stock available for use and average demand per day in matching units.
Related calculators
- Inventory Days Calculator — Estimate days of inventory using average inventory value and cost of goods sold over a chosen period.
- Safety Stock Calculator — Estimate buffer inventory using a service-level z value, demand variability and lead time.
- Inventory Shrinkage Calculator — Compare recorded inventory with a physical count and estimate shortage rate, overage and shortage cost.
- Days Payable Outstanding Calculator — Estimate days payable outstanding from average accounts payable and cost of goods sold for a chosen period.
- Days Sales Outstanding Calculator — Calculate days sales outstanding from average receivables and net credit sales over a matching period.
- Inventory Turnover Calculator — Estimate inventory turnover and days inventory on hand from cost of goods sold and average inventory value.
Related explanations
Learn the method behind the number or compare the terminology before using the calculator.
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This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.