You can run low-stock alerts on Shopify without paying for an app. Shopify's built-in Inventory report shows current on-hand stock; a simple spreadsheet with sales velocity and reorder point turns it into an alert you can check every Monday morning. This works up to a few hundred SKUs.
Below is a two-part workflow: use Shopify's report for the data, use the free reorder point calculator for the trigger, and log everything in a weekly review sheet.
Why skip the app
Inventory alert apps often start around $15–$30/month and quickly scale to $99+ as your catalog grows. If you have fewer than 500 SKUs and a single warehouse, a spreadsheet gives you 90% of the value at $0.
The apps become worth paying for when: you have multiple warehouses, more than 500 SKUs, or you need real-time push notifications rather than a weekly review.
The free workflow
- In Shopify Admin, go to Analytics > Reports > Inventory and export the current on-hand snapshot as CSV.
- Export your last 28 days of orders (Orders > Export).
- Open both in Google Sheets. Calculate 28-day units sold per SKU using SUMIF.
- Divide by 28 for daily sales velocity.
- Enter your supplier lead time (days) and safety cover (days) per SKU or per supplier.
- Compute reorder point = velocity × (lead time + safety cover). Use our Reorder Point Calculator to double-check.
- Sort by 'on-hand ≤ reorder point' — this is your weekly alert list.
- Place supplier orders for the SKUs on the alert list.
Send yourself a weekly reminder
Add a recurring Monday calendar event with a link to the sheet. That is the cheapest 'low-stock alert' possible — and the most reliable, because you own the check.
If you use Google Sheets, add a conditional format that highlights any row where days-of-cover is under your lead time. Any coloured cell means order today.
When to graduate to an app
- You cross ~500 active SKUs.
- You use two or more warehouses or a 3PL alongside self-fulfilment.
- You need push notifications rather than weekly checks.
- You sell on 3+ marketplaces and need per-channel splits.
Example calculation (USD)
Sample weekly review sheet
| SKU | On-hand | 28-day units | Velocity | Lead time | Safety | ROP | Alert? |
|---|---|---|---|---|---|---|---|
| SW-CRW-CHR-L | 72 | 112 | 4 | 21 | 7 | 112 | YES |
| SW-CRW-NVY-M | 210 | 84 | 3 | 21 | 7 | 84 | NO |
Common mistakes to avoid
- Setting one reorder point across all SKUs.
- Ignoring the safety cover for volatile products.
- Not counting incoming purchase orders.
- Only checking inventory when a customer complains.
- Missing a Monday review two weeks in a row.
Best practices
- Set a fixed weekly review time.
- Physical count top 10 SKUs monthly.
- Keep a small buffer for seasonal spikes.
- Track supplier lead time actuals, not promises.
- Log every stockout — it means the ROP was too low.
Frequently asked questions
Can Shopify itself send low-stock emails?
Not by default in every plan. Some plans expose an inventory threshold notification; check your current admin settings.
How do I forecast a brand new SKU?
Set velocity conservatively based on a similar product for the first 30 days, then use its own history.
What if my supplier lead time is unreliable?
Increase safety cover. Track actual lead time per PO and use the 90th percentile in your ROP formula.