How do you calculate tool crib inventory levels?

Multiply average daily usage by supplier lead time to get cycle stock, then add safety stock. With 85 units/day and an 85-day lead time in the defaults, cycle demand is huge relative to a 1,200-piece shelf, which is why the calculator returns only about 12.83 protected days of supply.

What is protected days of supply?

It is how many days your current inventory will last after accounting for the safety-stock buffer. The default run returns 12.83 protected days versus 14.12 unprotected days — the gap is the cushion the safety factor reserves.

What is a good safety stock factor for a tool crib?

Most cribs run a 1.1 to 1.5 multiplier on high-runners with reliable suppliers, higher for long-lead specialty tools. The default uses 1.1, a lean buffer that assumes dependable delivery.

Reorder point vs safety stock — what's the difference?

Safety stock is the fixed cushion below which you never want to drop; the reorder point is safety stock plus the demand expected during lead time. You trigger a purchase at the reorder point, not when you hit zero.

Why is my days of supply so low with 1,200 pieces on hand?

Because 85 units/day burns through 1,200 pieces in about two weeks. Inventory only looks big in absolute terms — measured against daily draw and an 85-day lead time, it is thin, which is exactly what the 12.83-day result flags.

How do I raise protected days of supply?

Increase on-hand quantity, cut supplier lead time, or reduce daily consumption per part through longer tool life. Shortening lead time is usually the cheapest lever because it directly reduces required cycle stock.

Tooling, Fixtures, Dies & Mold Economics calculator

Tool Crib Inventory Calculator

Tool crib inventory sizing tells a manufacturing plant how many perishable tools — inserts, drills, taps, end mills — to keep on the shelf so machines never wait on tooling. It is the classic reorder-point calculation applied to the crib: cycle stock covers demand during the supplier's lead time, and safety stock absorbs demand spikes and delivery slips. Crib attendants, tooling engineers and lean/materials planners use it to set min/max levels and reorder triggers. Get it wrong and you either starve spindles or tie up cash in a wall of unused carbide.

What this calculator does

Estimate tool crib inventory for tooling, fixtures, dies and mold economics using production-ready inputs so teams can plan replenishment and safety stock using actual usage and lead time.
Use it when tool crib inventory in tooling, fixtures, dies and mold economics is being sized for a buffer or safety stock review.
It converts on-hand tool inventory into protected days of supply given daily consumption, replenishment lead time and a safety-stock buffer.

Formula used

Tool crib inventory cycle stock = tool crib inventory daily usage × tool crib inventory lead time
Required tool crib inventory = cycle stock + tool crib inventory safety stock

Inputs explained

Average perishable tools consumed per day:
Supplier replenishment lead time:
Safety stock buffer multiplier:

How to use the result

Use it when setting reorder points and min/max levels for high-runner perishable tooling in the crib, or auditing whether current stock covers supplier lead time.
It assumes steady average daily usage; lumpy demand from a big job dropping onto the schedule can burn through stock far faster than the average implies.

Current U.S. benchmarks

The producer price index for plastic resins and materials stands at 319.371 (BLS, May 2026), up 19.5% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 14,378 furniture and related products establishments employing about 355,594 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate tool crib inventory levels? Multiply average daily usage by supplier lead time to get cycle stock, then add safety stock. With 85 units/day and an 85-day lead time in the defaults, cycle demand is huge relative to a 1,200-piece shelf, which is why the calculator returns only about 12.83 protected days of supply.
What is protected days of supply? It is how many days your current inventory will last after accounting for the safety-stock buffer. The default run returns 12.83 protected days versus 14.12 unprotected days — the gap is the cushion the safety factor reserves.
What is a good safety stock factor for a tool crib? Most cribs run a 1.1 to 1.5 multiplier on high-runners with reliable suppliers, higher for long-lead specialty tools. The default uses 1.1, a lean buffer that assumes dependable delivery.
Reorder point vs safety stock — what's the difference? Safety stock is the fixed cushion below which you never want to drop; the reorder point is safety stock plus the demand expected during lead time. You trigger a purchase at the reorder point, not when you hit zero.
Why is my days of supply so low with 1,200 pieces on hand? Because 85 units/day burns through 1,200 pieces in about two weeks. Inventory only looks big in absolute terms — measured against daily draw and an 85-day lead time, it is thin, which is exactly what the 12.83-day result flags.

Last reviewed 2026-05-12.