Inventory Management Calculators
Calculators to optimize stock levels, turnover, reorder points, and safety stock for retail and warehouses.
Inventory Turnover Calculator
Measure how many times a year your average inventory sells through and gets replaced. The single most consequential operational KPI in retail. It connects buying decisions, warehouse cash, markdown risk, and finance targets into one number. This calculator returns the turn ratio, converts it into days and weeks of supply, and shows how much working capital a one-turn improvement releases.
Inventory Turnover = COGS ÷ Average Inventory
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Reorder Point Calculator
Set the trigger level that fires the next PO for an SKU. Reorder point combines expected demand during lead time with a buffer for the weeks that run hot. Get either half wrong and you either stock out or bury cash on the shelf. This calculator returns the ROP, the lead-time demand, the buffer as a percent of expected demand, and the days of supply the ROP represents at current sales velocity.
ROP = (Daily Demand × Lead Time) + Safety Stock
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Safety Stock Calculator
Size the buffer that keeps shelves stocked when demand spikes or the truck runs late. Enter a target service level, your demand history, and lead time to get the exact number of units to hold above expected demand. No more guessing with "two extra weeks of supply."
Z × √(Lead Time × σD² + Daily Demand² × σLT²)
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EOQ Calculator
Find the order size that minimizes what you spend keeping an SKU stocked. Small orders push order cost up. Big orders push carrying cost up. EOQ finds the point where the two curves cross so you stop paying more than you have to, and it anchors every reorder point and safety stock decision downstream.
EOQ = √((2 × Annual Demand × Order Cost) ÷ Holding Cost)
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Days Inventory Outstanding Calculator
Convert your inventory position into a number finance actually reads: the average days of cash sitting on the warehouse floor. DIO is the same measurement as inventory turnover in days instead of a ratio, and it maps directly onto working capital, cash conversion cycle and reorder cadence. This calculator returns DIO, weeks of supply, implied turnover, and the exact cash a 10-day DIO improvement would release.
DIO = (Average Inventory ÷ COGS) × 365
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ABC Analysis Calculator
Paste a list of SKUs and their revenue and get an instant A / B / C classification. Use the output to set service levels, safety stock, and buying priority the way experienced planners do.
A: top 80% of cumulative revenue · B: next 15% · C: last 5%
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More Inventory Management resources
Guides, benchmarks and downloadable templates that pair with inventory management calculators.