How to plan inventory for a product launch

Start with an estimate, not a forecast

Before launch you have no sales data to work from. Use a demand estimate instead: look at similar products you already sell, check wishlist or waitlist signups if you have them, and factor in any marketing push planned for launch week. Pick a number you can defend, not a guess pulled from thin air.

Size the first order around lead time and risk

Your first purchase order needs to cover the supplier's lead time plus a launch buffer, because you cannot reorder fast if you sell out early. If lead time is 30 days and you expect to sell through your first batch in 45 days, order enough for roughly 60-75 days of estimated demand, not just 45. Running out in week one kills momentum, but overordering on an unproven product ties up cash in stock you may need to discount later.

Watch the first two to three weeks closely

Once real orders start coming in, compare actual daily sales against your estimate immediately. If actual demand is running well above or below plan, do not wait for a monthly review. Adjust your next order quantity and timing based on what is actually happening, not the original guess.

Plan the reorder trigger manually until history builds up

Set a manual reorder point for the first few months: daily sales (using your best current estimate) multiplied by lead time plus safety days. Update this number every time you get a new week of real data, since early sales trends can shift fast after a launch spike or a slow start.

Step by step

1. List 2-3 comparable existing products and note their first-month sales as a reference point
2. Add any waitlist, pre-order, or marketing reach numbers to refine your demand estimate
3. Calculate order quantity using lead time plus a launch buffer, not just expected sell-through time
4. Place the first purchase order early enough that stock lands before or right at launch day
5. Track daily sales against your estimate for the first two to three weeks without waiting for a full cycle
6. Recalculate your reorder point weekly using the newest sales data until you have steady history
7. Once you have roughly 13 months of data, let normal forecasting take over for this SKU

Worked example

Suppose you are launching a new candle scent. You estimate 300 units sold in the first two months based on how a similar scent performed last year. Your supplier's lead time is 20 days, so you add a 15-day launch buffer and order for 65 days of estimated demand: (300/60) x 65 = 325 units, rounded up to a case pack of 336. After two weeks you see actual sales of 8 units a day, higher than your 5-a-day estimate, so you recalculate: new reorder point is 8 x (20 + 7 safety days) = 216 units, and you move your next order date forward.

How SteadyShelf helps

SteadyShelf forecasts from a 28-day sales window, so it has nothing to work with for a brand new SKU and will not give useful numbers until real sales start accumulating. For the first few weeks after launch, size orders and reorder points manually as above, then let SteadyShelf take over once it has a few weeks of actual sales to work from.

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

SteadyShelf is launching on the Shopify App Store. Join early access to get the install link first.

Related guides

• How to plan inventory for a restock drop
• How to plan inventory for a sale or promotion
• How to plan inventory for a store selling in multiple countries
• How to plan inventory for a product feature in the press

All inventory how-to guides · Inventory glossary

FAQ