Ochrequiet invoicing

Inventory tools

Stock decisions, worked out exactly.

Five free tools for the questions that come up constantly when you carry physical stock: what to call it, how to mark it, when to reorder it, how much to order, and how fast it's actually moving. No account, no upload — everything runs in your own browser.

Reviewed 2026-08-11

Reorder point and EOQ answer different questions

It's easy to reach for one when you mean the other, because both come out of the same stock-planning problem. Reorder point answers when: the exact stock level, watched continuously, that should trigger your next purchase order. It's built from how fast you use stock and how long a new order takes to arrive, plus a buffer for when either one runs worse than average.

Economic Order Quantity answers a completely different question — how much to order once you've decided to place an order at all. It balances the cost of placing an order (which favors ordering rarely, in bulk) against the cost of holding stock (which favors ordering often, in small amounts), and finds the quantity where those two costs are lowest combined.

Run together, they tell the full story: reorder point tells your system when to fire a purchase order, and EOQ tells it how many units to put on that order. Neither one substitutes for the other, and a system using only one is only half planned.

Questions

What's the difference between reorder point and Economic Order Quantity?
Reorder point answers WHEN to order — the stock level that should trigger your next purchase order. Economic Order Quantity answers HOW MUCH to order once you've decided to place one. They're companion numbers that solve different problems; most inventory systems use both together, not one instead of the other.
Do I need all four of these tools, or just one?
Most businesses only need one or two at a time. If you're setting up products for the first time, start with the SKU generator. If you're deciding when and how much to reorder, use the reorder point and EOQ calculators together. Turnover is a review tool — useful periodically, not on every order.
Are these calculators accurate enough for real ordering decisions?
The arithmetic is exact — every calculator states its formula, substitutes your real numbers, and discloses its rounding. What they can't do is know your business: EOQ assumes constant demand and no quantity discounts, and reorder point is only as good as the usage and lead-time figures you put in. Use them as a documented starting point, then apply your own judgment.