How to use the ZenInventory
- Add each product with its name, SKU or code, quantity in stock and unit cost.
- Update quantities as stock comes in or goes out. The summary shows total items and stock value at a glance.
- Use the search and sort controls to find low-stock lines before they run out.
When to use it
Small retailers, market sellers, workshop owners and anyone running a modest online store often outgrow "I know roughly what is on the shelf" long before they can justify paid inventory software. This tool is the middle step: a single list of everything you hold, with quantities and values, that you can update from a laptop in the stockroom without an account or a subscription.
What each field is for
Product code is the identifier you will search by, so make it unique and short. Category groups lines for sorting. Initial stock is the count on the day you start; after that you adjust the quantity as stock moves. Unit says what "1" means (piece, kg, box of 12), which matters the day someone counts boxes and enters pieces. Price is the unit cost you paid, not the selling price, so that the stock value the summary shows is what your shelves are worth to you. Stock value is quantity × unit cost, summed over every line.
Worked example
A small café's dry store: "CF-001 Espresso beans, kg, 24 in stock at $18" ($432), "CF-002 Filter beans, kg, 9 at $16" ($144), "PK-010 Takeaway cups 12 oz, box of 500, 3 at $42" ($126), "MK-004 Oat milk 1 L, 30 at $1.90" ($57). Stock value $759. Sort by quantity and the filter beans are near the bottom with a delivery six days away: that is the reorder signal, and the purchase order goes out the same day, referencing the product codes so the delivery note can be checked line by line.
Common mistakes
- Selling price in the price field. The stock value becomes what you hope to sell it for, not what it cost, and your accountant will have to redo it.
- Mixed units on one line. Cups counted in boxes one week and in pieces the next make the number meaningless.
- Adjusting the count from memory. Update it when stock physically moves, or once a week from a real count, not both.
- No backup. The list lives in this browser. Export regularly.
When this tool is the wrong one
It is a single list with a value total. It does not record movements, does not know about suppliers, reorder points or sales, and does not sync between devices. Once you need to know what sold rather than what is left, or you have two people updating stock, that is inventory software. For the money side of the same month, the Expense Tracker.
Good to know
Your list is stored in this browser on this device, which is what makes it private and free, and also means it is not shared between machines; export or note important figures before switching computers. It tracks quantities you enter by hand and does not connect to a till or a marketplace.