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Inventory Days On Hand Calculator — DOH Benchmark & Overstock Cost

Calculate inventory days on hand (DOH) and compare to industry benchmarks. Identify excess inventory and quantify the annual carrying cost of overstock.

Quick answer: Inventory days on hand by industry: Grocery 15–25 days, Electronics 30–60 days, Automotive parts 30–90 days, Industrial B2B 60–120 days. Every 10 days of excess inventory on $5M stock = $34,000/year in avoidable carrying cost.

📅 Inventory Days On Hand Calculator

Days on Hand
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Excess Inventory Value
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Annual Excess Carry Cost
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How to Use This Calculator

  1. Enter average inventory and COGS — use 13-week average inventory for a more accurate DOH than month-end snapshot.
  2. Select your industry — auto-fills the benchmark DOH. Adjust the target for your specific business model.
  3. Review excess carrying cost — every dollar of excess inventory costs 25% of its value in annual carrying cost — make this visible to purchasing and planning teams.

Worked Example

$4.5M inventory, $18M COGS, Electronics benchmark 45 days, 25% carrying rate.

  1. Actual DOH: $4.5M ÷ $18M × 365 = 91.25 days
  2. Target inventory: 45 × ($18M ÷ 365) = $2.22M
  3. Excess: $2.28M
  4. Annual carry cost: $570,000

At 2× the benchmark DOH, there's $570K in annual excess carrying cost. Reducing to 60 days (still above benchmark) frees $1.28M in cash and saves $319K/year in carrying cost.

Frequently Asked Questions

Reduce safety stock through better demand forecasting. Negotiate shorter supplier lead times (see Lead Time Cost Calculator). Implement min/max reorder points by SKU. Run quarterly excess/obsolete inventory reviews with markdown or return-to-vendor actions. ABC analysis — carry more A-items, less of C-items.

Below your safety stock + cycle stock requirement. For a 95% service level with a 14-day lead time, you need at minimum 14 days of demand inventory plus safety stock. Going below this risks stockouts and emergency freight. DOH too low is just as costly as DOH too high — just in different ways.