Calculator Inputs
This page uses a single-column section flow, while input groups switch to three columns on large screens, two on smaller screens, and one on mobile.
Example Data Table
Use this sample to test the calculator and verify the result flow.
| Planning Item | Example Value |
|---|---|
| Incoming Units | 4,200 |
| Monthly Demand | 9,000 |
| Days in Month | 30 |
| Lead Time Days | 12 |
| Safety Stock Days | 8 |
| Reorder Cycle Days | 15 |
| Capacity Buffer % | 10 |
| Allocation Objective | Balanced |
| Warehouse | Usable Capacity | Current Stock | Reserved Stock | Demand Share % | Storage | Handling | Shipping | Service Score | Priority |
|---|---|---|---|---|---|---|---|---|---|
| East Hub | 4,000 | 900 | 200 | 40 | 0.85 | 0.55 | 1.45 | 9 | 5 |
| Central Hub | 5,200 | 1,100 | 250 | 35 | 0.75 | 0.60 | 1.35 | 8 | 4 |
| West Hub | 3,600 | 600 | 150 | 25 | 0.90 | 0.50 | 1.70 | 7 | 3 |
Formula Used
1) Daily demand
Daily Demand = Monthly Demand ÷ Days in Month
2) Target network stock
Target Network Stock = Daily Demand × (Lead Time + Safety Stock Days + Reorder Cycle Days)
3) Buffered capacity
Buffered Capacity = Usable Capacity × (1 − Capacity Buffer %)
4) Free capacity
Free Capacity = Buffered Capacity − Current Stock − Reserved Stock
5) Landed variable cost
Landed Cost / Unit = Storage + Handling + Shipping
6) Composite warehouse score
Score = weighted mix of demand factor, service, capacity, inverse cost, and priority. The exact weights change with the selected objective.
7) Allocation logic
Incoming units are distributed using each warehouse score, but never above free capacity. Any excess beyond buffered free capacity becomes unallocated overflow.
How to Use This Calculator
Step 1
Enter the incoming inventory quantity for the current replenishment cycle.
Step 2
Add network demand, planning days, lead time, safety days, and reorder cycle days.
Step 3
Set a capacity buffer so the model preserves storage headroom for peaks and slotting changes.
Step 4
Complete all warehouse rows with capacity, stock, demand share, cost, service score, and priority weight.
Step 5
Choose an objective. Balanced is general planning, Lowest Cost reduces expense, Fastest Service favors service, and Capacity Protection preserves room.
Step 6
Click Calculate Allocation. Review the summary, graph, detailed table, score table, and export the results to CSV or PDF.
FAQs
1. What does this calculator optimize?
It balances incoming units across warehouses using demand share, service quality, free capacity, unit cost, and business priority. The selected objective changes the weighting mix.
2. Why is there a capacity buffer?
The buffer leaves operational headroom for slotting changes, cycle count issues, returns, and inbound volatility. It prevents the recommendation from filling every usable location.
3. What happens if demand shares do not total 100%?
The calculator normalizes them automatically. That keeps relative demand importance intact while ensuring the scoring and target stock calculations still work correctly.
4. What are reserved units?
Reserved units are stock already committed to orders, channels, or internal holds. They consume capacity, but the model does not treat them as new incoming inventory to allocate.
5. Why can overflow remain unallocated?
If incoming units exceed buffered free capacity, the excess cannot be placed safely. The tool flags those units so you can plan overflow storage, transfers, or another receipt window.
6. When should I use Lowest Cost mode?
Use it when freight, handling, and storage expense matter more than speed. This mode gives a stronger advantage to warehouses with lower unit economics.
7. When should I use Fastest Service mode?
Use it when customer delivery experience matters most. Warehouses with higher service scores receive more weight, even if their unit cost is not the cheapest.
8. Can I use this for transfer planning too?
Yes. Treat transfer stock as incoming units and update current or reserved positions before calculation. The output becomes a practical guide for where the stock should land.