Inventory how-to

How to plan inventory for a restock drop

Plan a restock drop by deciding how many days of demand you want the drop to cover, then order enough stock to land before the drop date with a buffer for early sales.

Short answer: Plan a restock drop by deciding how many days of demand you want the drop to cover, then order enough stock to land before the drop date with a buffer for early sales. Use your last drop or your recent sales rate per variant as the base, not gut feel.

Start from demand, not from a round number

Look at sales per variant from the last drop, or if this is new, from the closest comparable product. Decide how many days you want the restock to last before the next drop or before normal reorder cycles pick up. That number of days, times your expected daily sales, is your base order quantity.

Add a buffer for the spike

Drops sell faster in the first hours or days than normal daily sales. If your normal daily rate is 5 units but a drop compresses a week of sales into one day, use the compressed rate for the first day or two, then your normal rate for the rest of the cover period. Round up, not down, since understocking a drop is worse than a bit of leftover stock.

Work backwards from the drop date

Take the supplier's lead time plus your safety days and count back from the date you want stock in hand. That is your order-by date. If the supplier needs 20 days and you want 5 days of buffer before the drop, place the order at least 25 days before the drop date.

Account for case packs and minimums

Suppliers often sell in case packs or have minimum order quantities. Round your calculated need up to the nearest case pack. If that pushes you well above what you need, check if a smaller pack size or split order is possible, otherwise accept the extra stock as a cost of doing the drop.

Step by step

  1. List the variants going into the drop and pull their recent sales history.
  2. Estimate the drop-day sales rate separately from the normal daily rate.
  3. Set your target days of cover for the drop and calculate base quantity: expected units per day x days of cover.
  4. Add safety stock for demand you can't predict, especially for a first-time or marketing-pushed drop.
  5. Check supplier lead time and safety days, then work backwards to get your order-by date.
  6. Round the order up to case pack and minimum order requirements.
  7. Place the order early enough to allow for supplier delays, since a late restock drop is a bigger problem than a slightly late routine reorder.

Worked example

Say you are planning a sneaker restock drop for a variant that normally sells 3 units a day. On past drop days this same variant sold 60 units in the first 24 hours, then settled back to normal demand. You want 7 days of stock after the drop: 60 units for day one, plus 3 x 6 = 18 units for the rest, giving a base need of 78 units. You currently hold 10 units and have none on order, so order quantity = 78 - 10 = 68 units. Your supplier's case pack is 12, so you round up to 72 units. Lead time is 15 days and you want 5 safety days, so you place the order 20 days before the drop date.

How SteadyShelf helps

SteadyShelf forecasts from your regular 28-day sales window and seasonality patterns, so it is built for steady reorder cycles, not for predicting a one-off spike like a drop. You will need to manually estimate the drop-day spike quantity and either place that order yourself or temporarily adjust the suggested quantity before approving the purchase order in SteadyShelf.

$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

Can SteadyShelf automatically detect that a restock drop is coming and adjust its forecast?

No. SteadyShelf's forecast is based on recent sales history and seasonality once you have about 13 months of data. It does not know about planned marketing events or drops, so you need to manually factor in the expected spike when deciding quantities for a drop.

Should I set up a separate reorder point for drop variants?

SteadyShelf's reorder point is calculated from daily sales times lead time plus safety days, using your regular sales pattern. For a drop, it is more reliable to calculate the one-off order quantity by hand using the drop-specific numbers, then place or edit the purchase order manually rather than relying on the automatic reorder point for that SKU.

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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