Enter SKU and storage details
Example SKU placement table
Use this as a reference when scoring multiple products.
| SKU | Monthly Demand | Picks/Day | Unit Volume (cm³) | Profit/Unit | ABC | Score | Recommended Zone | Req. Locations |
|---|---|---|---|---|---|---|---|---|
| SKU-FAST-01 | 2,800 | 45.0 | 1,800 | 8.50 | A | 88.6 | Fast Pick (A Zone) | 6 |
| SKU-STD-14 | 1,100 | 14.0 | 3,900 | 5.20 | B | 66.9 | Standard Pick (B Zone) | 3 |
| SKU-RES-77 | 420 | 3.2 | 6,500 | 3.10 | C | 44.8 | Reserve (C Zone) | 2 |
| SKU-BULK-09 | 380 | 2.5 | 62,000 | 11.40 | B | 53.2 | Oversize / Bulk Zone | 4 |
| SKU-SLOW-55 | 120 | 0.6 | 4,100 | 2.40 | C | 31.7 | Deep Reserve / Slow Movers | 1 |
Tip: Export each SKU result to CSV, then combine them in a spreadsheet for batch slotting.
Formula used
- Demand/day = Monthly Demand ÷ 30
- σ/day = Demand/day × (Variability% ÷ 100)
- Safety Stock = Z × σ/day × √(Lead Time days)
- Reorder Point = (Demand/day × Lead Time) + Safety Stock
- Higher service level increases the Z value and buffer.
- Annual Demand = Monthly Demand × 12
- Holding Cost/Unit = Unit Cost × (Holding Rate% ÷ 100)
- EOQ = √(2 × Annual Demand × Order Cost ÷ Holding Cost/Unit)
- Velocity uses a log scale of picks/day.
- Value uses monthly contribution tiers (profit × demand).
- Score = 40% Velocity + 35% Value + 15% Size + 10% Weight.
- Oversize/heavy items override zone suggestions.
If you have true demand standard deviation, replace the variability estimate for a tighter buffer.
How to use this calculator
- Enter one SKU and realistic demand and picking frequency.
- Fill unit size, weight, and your supplier lead time.
- Choose service level and variability based on history.
- Enter order cost and annual holding rate for EOQ.
- Set pick-face capacity and available locations.
- Click
Calculate placementto view results above the form. - Download CSV or PDF to share with operations.
- Repeat per SKU and combine exports for full slotting.
Demand velocity and travel workload
Slotting starts with picking velocity. If a SKU is picked 18 times per day and the average one-way distance to packing is 18 meters, a round trip is about 36 meters. Daily walking tied to that SKU is roughly 648 meters (36 × 18). The calculator applies a zone factor to estimate walk change: fast pick uses 0.70, standard pick 0.85, reserve 1.05, and deep reserve 1.15. This turns velocity into a workload signal you can compare across products during peak promotions and launches.
Safety stock and service level trade-offs
Replenishment protection is driven by lead time and variability. Demand per day is Monthly Demand ÷ 30, and daily variability is modeled as σ/day = Demand/day × Variability%. Safety stock is Z × σ/day × √(Lead Time). Z is selected from practical targets: 80%≈0.84, 90%≈1.28, 95%≈1.65, and 99%≈2.33. Higher service levels increase buffer units and raise the reorder point, improving availability while consuming pick-face space.
EOQ as a cost-balanced order size
EOQ balances inbound work against storage cost. Annual Demand = Monthly Demand × 12, and Holding Cost/Unit = Unit Cost × Holding Rate%. Example: 14,400 units/year, order cost 35, unit cost 12, holding rate 24% gives holding cost 2.88 per unit-year. EOQ ≈ √(2 × 14,400 × 35 ÷ 2.88) ≈ 592 units, which sets a practical cycle stock of about 296 units.
Pick-face utilization and location planning
Target stock is Reorder Point + (EOQ ÷ 2). Required pick locations = ceil(Target Stock ÷ Location Capacity). Utilization is Target Stock ÷ (Location Capacity × Locations Available). When utilization exceeds about 90%, congestion risk rises: replenishment frequency increases, pick errors climb, and restock tasks interrupt waves. If required locations exceed available slots, use reserve storage plus split-case replenishment or increase capacity.
Placement score governance and overrides
The placement score combines velocity (40%), contribution value (35%), size friendliness (15%), and weight friendliness (10%) into a 0–100 index. Scores map to zones: 80+ fast pick, 60–79 standard pick, 40–59 reserve, below 40 deep reserve. ABC class is based on monthly contribution (profit × demand). Oversize and heavy thresholds override the zone to protect safety and handling efficiency.
FAQs
Enter monthly demand, picks per day, unit cost, unit price, lead time, variability, and at least one pick location capacity value. These fields drive the reorder point, safety stock, EOQ, and zone recommendation.
It blends velocity, contribution value, size, and weight into a 0–100 score using fixed weights (40/35/15/10). Higher picks and higher contribution raise the score; larger or heavier items reduce it.
ABC is based on monthly contribution (profit per unit × monthly demand). A items are high contributors, B are mid-range, and C are lower contributors. Use it to prioritize slotting changes and cycle counts.
Override when items are oversize, heavy, fragile, regulated, or require special handling equipment. Also override if the pick-face utilization is too high, or if replenishment routes make the suggested zone impractical.
Yes. Run each SKU, export CSV, and combine files in a spreadsheet. Sort by placement score, ABC class, and required locations to build a prioritized slotting list for re-layout planning.
Exports include the SKU, demand, lead time, safety stock, reorder point, EOQ, target stock, utilization, scoring components, and the recommended zone with notes. Use PDF for sharing; use CSV for analysis.