TL;DR
Inventory days on hand is the average number of days of forward sales currently held in inventory — calculated as inventory units divided by average daily sales velocity. For D2C consumables, healthy DOH is 45–75 days; for apparel, 90–120 days; for durables, often 120+ days. Inventory DOH is the central operating metric for working-capital management and stockout-risk planning.
What is inventory days on hand?
Inventory days on hand (often abbreviated 'DOH' or 'days of supply') is the average number of days that current inventory will cover at recent sales velocity. It is the inventory-side complement to weeks of supply (the same metric expressed in weeks rather than days).
It is the central operating metric for working-capital management because it sits at the intersection of two competing pressures: too little inventory creates stockout risk, while too much inventory consumes cash and increases markdown risk.
How to calculate it
The trailing window matters: too short and the velocity estimate is noisy; too long and recent demand changes don't show up. 28 days is a good default for most D2C categories.
Inventory Days on Hand = (current inventory units) / (average daily sales velocity) Where average daily sales velocity = (units sold over trailing N days) / N Recommended trailing window: 28 days for stable categories, 14 days for fast-moving or seasonal categories.
Benchmarks by category
| Category | Healthy DOH | Caution | Critical |
|---|---|---|---|
| D2C Consumables | 45–75 | <30 or >90 | <15 or >120 |
| Apparel | 90–120 | <60 or >150 | <30 or >180 |
| Durables | 120–180 | <90 or >240 | <60 or >300 |
| Subscription-eligible consumables | 30–60 | <20 or >75 | <10 or >100 |
Common pitfalls
- 1. Using a single brand-level DOH for SKU planning. Brand-level averages hide SKU-level extremes — your top 10 SKUs may have 12 days of supply while bottom-quartile SKUs have 400 days. SKU-level DOH is the only actionable view for purchasing and markdown decisions.
- 2. Calculating DOH on retail sales velocity but ordering on wholesale lead time. If you sell through both DTC and wholesale channels, DOH calculated on combined velocity is fine for working-capital math but useless for purchase-order timing — wholesale orders need lead-time-aligned planning.
- 3. Ignoring in-transit inventory. Inventory currently on a boat from a manufacturer counts toward future supply. Excluding it from DOH calculations causes over-ordering. Healthy inventory math separates 'on-hand' from 'in-transit' and reports both.
Related concepts
Weeks of supply is the same metric in weeks. Stockout rate is the downside of low DOH. Markdown rate is the downside of high DOH. GMROI measures the inventory-investment efficiency.
At a glance
- Category
- Operations / Cash
- Related
- 5 terms
Frequently asked questions
What's a healthy inventory DOH?
Depends on category and lead time. Consumables: 45–75 days. Apparel: 90–120 days. Durables: 120+ days. The right answer is roughly: replenishment lead time + safety stock for demand variability + buffer for forecast error. Anything beyond that is excess working capital.
How is DOH different from weeks of supply?
Same metric, different unit. DOH expresses the answer in days; weeks of supply expresses the answer in weeks. Operators tend to use DOH for fast-moving consumables and weeks-of-supply for apparel and seasonal categories.
Should you include in-transit inventory?
Track separately. Pure on-hand DOH is the right number for shipping-fulfilment availability. On-hand + in-transit DOH is the right number for purchase-order timing decisions. Reporting both is the cleanest pattern.
Sources
- NRF inventory benchmarks (2024)
- Shopify D2C operating data
- Fairview customer data (D2C, 2025)
Fairview is an operating intelligence platform that computes inventory DOH per SKU using rolling 28-day velocity, segmenting on-hand from in-transit and flagging stockout and overstock risk before they materialise. Start your free trial →
Siddharth Gangal is the founder of Fairview. He built the SKU-level DOH layer after watching D2C brands order against brand-aggregate forecasts that masked which 8% of SKUs were on the verge of stockout and which 12% were sitting on 200+ days of supply — both pathologies hidden inside a healthy-looking aggregate number.
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