Inventory how-to

How much inventory should a new Shopify store buy

Buy less than you think.

Short answer: Buy less than you think. With no sales history, pick a small test quantity per variant, enough to cover 4 to 6 weeks, and plan your first reorder based on actual sales instead of a guess. Spread your budget across fewer SKUs with deeper test buys rather than many SKUs with thin stock.

Start from budget, not from forecast

A new store has no sales data, so any forecast is a guess dressed up as math. A better approach is to decide how much cash you can tie up in stock, then split it across your SKUs by how confident you are in each one. Put more weight on your core, proven-demand items and less on untested variants like new colors or sizes.

Use case packs and supplier minimums as your floor

Your supplier's case pack size and minimum order quantity often set the real lower limit, regardless of what a forecast says. If a supplier sells in cases of 24, you buy 24 or 48, not 10. Know these numbers before you plan quantities, because they decide your real starting inventory more than any formula does.

Watch the first 4 to 6 weeks closely

Once the store is live, track sales daily or weekly per variant. The first real signal you get is which variants sell faster than expected and which sit still. Use that early read to decide what to reorder and what to cut, rather than waiting for a full season to pass.

Avoid the two common mistakes

New stores either overbuy because a supplier pushed a bulk discount, or underbuy out of caution and then stock out during their first marketing push. Both are expensive: one ties up cash in slow stock, the other kills momentum right when people are discovering you. Size your first order to survive a modest demand spike, not a guess at a huge one.

Step by step

  1. List every variant and tag it by confidence: core item, likely seller, or untested
  2. Set a total inventory budget you are comfortable not selling through immediately
  3. For core items, buy enough for about 6 weeks of expected sales, rounded up to the case pack
  4. For untested variants, buy the supplier's minimum order quantity and no more
  5. Confirm each supplier's lead time before you order, so you know when you will need to reorder
  6. After 2 to 3 weeks of real sales, recalculate using actual daily sales, not your original guess
  7. Reorder only the SKUs showing real demand, and consider discontinuing ones that do not move

Worked example

Say you are launching a store with three T-shirt colors. You expect roughly 2 units a day per color once live, but you have no history yet. Your supplier's case pack is 25 units with a 10-day lead time, so you order one case of 25 per color, which covers about 12 days of expected sales plus a buffer. After two weeks of real sales, black is selling 4 units a day and white only 0.5 a day. Reorder point for black becomes 4 x (10 + 3 safety days) = 52 units, so you order another case well before you run out, while you let white run down before reordering more.

How SteadyShelf helps

SteadyShelf needs about 28 days of sales history to start forecasting, so it cannot size your very first order for a brand new store. Once you have a few weeks of real sales in Shopify, it picks up from there, calculates reorder points per SKU, and tells you when to place your next order based on each supplier's lead time and case pack.

$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.

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FAQ

Should I order different quantities for each variant like size or color?

Yes. Treat each variant as its own line with its own expected demand and its own case pack rounding, rather than splitting one total evenly. Sizes and colors rarely sell at the same rate, and an even split usually overstocks the slow ones and understocks the fast ones.

What if my supplier has a long lead time, like 8 weeks?

A long lead time means your first order has to cover the full lead time plus a safety buffer, since you cannot top up quickly if you misjudge demand. In that case lean toward your proven, core items for the bulk of the order and keep untested variants to the supplier's minimum, since you are committing to a long wait before you can correct course.

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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