Track inventory efficiency across channels, stores, and marketplaces. Estimate cash tied up in stock today. Set targets, spot risk, and plan smarter reorders weekly.
Choose how you want to provide inventory and cost inputs. The calculator will compute days on hand, turnover, and a practical inventory health signal.
| Days | Beginning inventory | Ending inventory | Average inventory | COGS | Turnover | Inventory days |
|---|---|---|---|---|---|---|
| 365 | $25,000 | $35,000 | $30,000 | $180,000 | 6.00× | 60.83 days |
If you provide revenue and gross margin, COGS is estimated as Revenue × (1 − Gross Margin%).
Inventory days on hand converts stock value into time, so teams can compare product lines with different prices. If your period COGS is $180,000 over 365 days, daily COGS is about $493. When average inventory is $30,000, days on hand is roughly 60.8. That single number helps forecast when cash returns from inventory. Teams translate this into reorder coverage by location in practice.
Accurate results depend on aligned inputs. Use the same period for inventory and costs: monthly inventory with annual COGS will distort days. If you lack COGS, derive it from revenue and margin. For example, $300,000 revenue at 40% margin implies COGS near $180,000. For brands using units, multiplying units sold by unit cost keeps the calculation consistent. Exclude taxes, shipping, and refunds when estimating margin.
Turnover and days are two views of the same relationship. Turnover equals COGS divided by average inventory, so higher turnover means fewer days. A turnover of 6× implies about 61 days on a 365‑day window. When turnover falls to 3×, days roughly double, signaling slower demand, buy quantities, or excess safety stock.
Targets work best when tied to lead time and service level. If supplier lead time is 21 days and you hold 14 days of safety stock, a 35‑day target can be realistic for fast movers. For seasonal lines, raise targets before peak, lower after. Translating a 60‑day target into dollars (daily COGS × 60) clarifies how much working capital is tied up.
Use segmentation to find what the headline metric hides. Compute inventory days by channel, warehouse, or category, then compare dispersion. If your blended result is 60 days but one category sits at 140 days, that group is driving storage and markdown risk. Pair days with aging buckets, sell‑through, and return rates to spot problem SKUs. A top‑ten SKU table explains variance quickly.
Operational actions should map to the status signal. Low days suggest stockout risk: shorten reorder cadence, raise reorder points, or expedite purchase orders for top sellers. High days suggest overstock risk: test bundles, price ladders, and clearance rules, and renegotiate MOQs. Recalculate weekly, track trends, and set alerts when days move 15–20% from target.
1) What is inventory days on hand?
Inventory days on hand estimates how many days your current average inventory can support sales, based on COGS for the same period. Lower values mean faster inventory movement; higher values suggest slower sales or heavier stocking.
2) Which period should I use?
Use the period you report costs for: 30, 90, or 365 days. Inventory and COGS must cover the same window. If you compare months, keep the day count and cost method consistent across months.
3) Can I calculate without COGS?
Yes. If you know revenue and gross margin, COGS can be estimated as Revenue × (1 − Margin%). Example: $100,000 revenue at 35% margin implies about $65,000 COGS. Accuracy depends on clean margin inputs.
4) What target days should I set?
Start with lead time plus safety stock coverage. If lead time is 20 days and you want 10 days buffer, a 30‑day target is reasonable for fast movers. Slow or seasonal items may need different targets by category.
5) Why does turnover look high or low?
Turnover rises when COGS increases or inventory falls. It drops when you buy ahead, demand slows, or unit costs change. Check whether inventory is valued consistently, and ensure returns, write‑offs, and freight are treated the same way each period.
6) How should I act on overstock risk?
Reduce future purchases, prioritize sell‑through, and review pricing. Move slow items with bundles, targeted discounts, or channel expansion. For repeats, tighten minimum order quantities and revisit reorder points so stock matches demand and lead time.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.