Inventory how-to

How to plan inventory for back to school

Plan back to school inventory by treating it as a known seasonal spike: pull last year's numbers for the same weeks, set your order-by dates early enough to cover supplier lead time plus the ramp-up in demand, and order in rounds rather than one big guess.

Short answer: Plan back to school inventory by treating it as a known seasonal spike: pull last year's numbers for the same weeks, set your order-by dates early enough to cover supplier lead time plus the ramp-up in demand, and order in rounds rather than one big guess. The main risk is ordering too late, not too much.

Start with last year's actual sales

If your store was open last back to school season, look at daily sales per SKU for the four to six weeks before and during the rush. This is your best signal, better than guessing a growth percentage. If you do not have last year's data, use your most recent 28 days as a baseline and adjust up manually based on what you know about the category.

Work backwards from the date demand starts

Back to school demand usually builds before the actual date on the calendar. Pick the date you expect sales to start climbing, then subtract your supplier's lead time and a safety buffer to get your order-by date. If a supplier takes 3 weeks to ship and you want stock on shelf 2 weeks before the rush, you need to place the order at least 5 weeks before the rush begins.

Order in two rounds instead of one

Splitting into an initial order and a top-up order reduces the damage from a bad forecast. Place a first order sized for a conservative case, then watch sell-through in the first week or two of the season and place a second order for fast movers while there is still enough lead time left.

Watch fast movers daily during the season

Once the season starts, daily sales can shift quickly from your forecast. Check your top SKUs by volume every few days and compare against days of stock remaining, so you catch a stockout risk while there is still time to reorder.

Step by step

  1. Pull last year's daily sales per SKU for the back to school weeks, or use your last 28 days if you have no history
  2. Pick the date you expect demand to start rising this year
  3. Subtract supplier lead time and a safety buffer from that date to get your order-by date
  4. Size a first order using daily sales x (lead time + days of cover) minus what you already have on hand or on order
  5. Round the order up to your supplier's case pack and minimum order quantity
  6. Place the order by the order-by date, not later
  7. Track sell-through weekly once the season starts and place a top-up order for anything selling faster than forecast

Worked example

Last year a notebook SKU sold 6 units a day during the back to school weeks. Supplier lead time is 21 days and you want 10 days of safety stock, plus 20 days of cover once stock arrives. Order quantity = 6 x (21 + 10 + 20) - (40 on hand + 0 on order) = 6 x 51 - 40 = 266 units. You round that up to 280 to match the supplier's case pack of 20.

How SteadyShelf helps

SteadyShelf can calculate the order-by date and suggested quantity per SKU once it has your sales history, including seasonality if you have about 13 months of data, and it rounds to your supplier's case packs automatically. It does not build a separate back to school forecast model or know about external trends, so for a new or unusually large seasonal push you should still sanity check the suggested quantities against what you know about the category.

$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

What if this is my first back to school season and I have no sales history?

Use your most recent 28 days of sales as a baseline, then adjust manually based on category knowledge, like how similar stores or similar products tend to move in that period. Order a conservative first round and plan a fast top-up order once you see real sell-through, since your forecast confidence is lower without history.

Should I order everything at once to get a better supplier price?

A bulk discount is only worth it if you are confident in the quantity. For a seasonal spike with forecast risk, ordering in two rounds usually costs less overall than sitting on unsold stock after the season, even if the per-unit price is slightly higher on the smaller first order.

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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