Inventory how-to

How to plan inventory for Christmas

Start earlier than you think you need to, work backwards from each supplier's lead time, and size orders using last year's holiday numbers plus your current growth rate rather than normal 28-day averages.

Short answer: Start earlier than you think you need to, work backwards from each supplier's lead time, and size orders using last year's holiday numbers plus your current growth rate rather than normal 28-day averages. Treat Christmas as a separate planning exercise from your regular reorder cycle, because standard forecasts are built for steady demand, not spikes.

Work backwards from your last safe order date

Find out each supplier's lead time and add your safety days, then count backwards from Christmas delivery deadlines (yours, not the carrier's). A supplier with a 30-day lead time needs an order placed by late November at the latest for a mid-December delivery, and that assumes no delays. Build in extra safety days for the holiday period itself, since carriers and suppliers slow down in December.

Use last year's numbers, not this year's average

Your regular daily sales average will understate what you need for peak weeks. Pull last December's daily sales per SKU, or per similar SKU if the product is new, and use that as your base rate instead of the trailing 28-day figure. Adjust up or down for known changes like a bigger ad budget, a new wholesale account, or a product you've since discontinued.

Separate "always needed" SKUs from "seasonal only" SKUs

Identify which products are your steady sellers that also spike at Christmas, versus items that only exist for the gifting season. Steady sellers need a blended plan: enough for daily demand plus a bump for the holiday weeks. Seasonal-only items need a single large order sized to sell through, since reordering mid-December from most suppliers won't arrive in time.

Order in stages if your cash flow allows it

If you can't commit to one large order months out, split it into two or three POs: an initial stock-up order in October or early November, and a top-up order once you see how sell-through is tracking. This reduces the risk of over-ordering slow sellers while still covering your fast movers.

Plan your post-Christmas position too

Decide what happens to leftover seasonal stock before you order it. If a product won't sell outside the holiday window, order tighter and accept you might sell out, rather than sitting on dead stock into January.

Step by step

  1. List every SKU you expect to sell more of at Christmas, including new seasonal items.
  2. Get each supplier's lead time and add extra safety days for December slowdowns.
  3. Pull last year's daily sales for the holiday window per SKU, or use a comparable SKU if new.
  4. Calculate order quantity using daily rate x (lead time + days of cover) minus stock on hand and on order.
  5. Round up to the nearest case pack and check against supplier minimums.
  6. Place early orders in October or November for anything with a long lead time.
  7. Decide a plan for leftover seasonal stock before you place the order.

Worked example

A store sells a gift set at 4 units/day normally, but last December it sold 20 units/day for three weeks. This year the store is up 25% year over year, so it plans for 25 units/day during that window. The supplier has a 20-day lead time and the store wants 10 days of safety stock for the season. Order quantity = 25 x (20 + 10) minus (on hand + on order) = 750 minus 60 on hand = 690 units, rounded up to the nearest case pack of 50, so 700 units ordered.

How SteadyShelf helps

SteadyShelf's forecast is seasonality-aware once a SKU has about 13 months of history, so returning holiday items will get a better forecast in year two and beyond. It does not do manual demand planning for growth assumptions or brand-new seasonal SKUs, so for those you still need to pull last year's numbers yourself and adjust the suggested quantity before approving the PO.

$29/month flat, unlimited products and suppliers, 30-day free trial. Run the numbers now with the free reorder point calculator.

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FAQ

Will SteadyShelf automatically know to order more for Christmas?

Yes, but with caution. Early in a product's life it only has the current 28-day window, so its first forecast will not reflect last year's holiday spike. Once a SKU has about 13 months of sales history, the forecast starts factoring in seasonality.

What if I miss the order-by date for a supplier?

Set a cutoff date for each supplier, usually mid-November for domestic suppliers and earlier for overseas ones, based on their lead time plus safety days. After that date, placing a normal cycle order risks arriving after Christmas, so you need to either expedite or accept the stockout.

Let SteadyShelf do this math for every SKU

Order-by dates per supplier, seasonal forecasts and draft POs for your Shopify store. $29/month after a 30-day free trial.

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