Inventory forecasting

Know what to reorder before it runs out

Posto forecasts every product in your Shopify store from its own sales, leaves out days you were sold out, times each order by how long that supplier really takes, and plans for Black Friday and the holidays. Every recommendation shows the math, so you can check it.

See exactly how Posto calculatesStart 30 days free

Why reordering is harder than it looks

A simple average of recent sales feels safe, but it misses things. Days you were sold out look like days nobody wanted the product, so the next order comes out too small, right when you need more.

It also forgets what's already on order, trusts the lead time your supplier quoted instead of how long deliveries really take, and treats November like any other month. Multiply that by every product and every supplier, and a spreadsheet stops keeping up.

Posto uses standard inventory math, not AI. If a number looks wrong, the breakdown shows you why.

What Posto works out, and what you decide

Posto works out
  • How much each product really sells
  • When to reorder
  • How much to order
It keeps these current every day, from live Shopify sales and stock.
You decide
  • Your supplier rules
  • How much cushion you want
Set each supplier's lead time, minimum, and case pack, and pick a service level. Once 3 orders from a supplier have arrived, Posto switches to how long they really took and labels it "measured." Posto's defaults are a sensible place to start.

How a recommendation comes together

1

Read your real demand

Posto averages each product's daily sales, counting only days it was for sale and in stock. New products are marked "Limited history" until there's enough to go on.

2

Look ahead

It projects demand forward along each product's recent trend, then adds Black Friday, Cyber Monday, and the holiday peak on top. You can adjust each event or turn it off.

3

Set when and how much

It sets a reorder point that covers your supplier's lead time, measured from real deliveries once there are 3, plus a safety buffer. Then it counts stock already on order and rounds the order to your supplier's minimum and case pack.

Every number has a "Why this quantity?" breakdown, and the most urgent products come first.Slow, uneven sellers get a buffer sized for small, lumpy demand.Optional daily or weekly emails list everything that needs reordering.

Your first forecast is ready right away

Posto starts forecasting from your Shopify sales as soon as you install. Add your suppliers' lead times to sharpen it, then fine-tune the rest whenever you're ready.

Try it on a product you know wellPick a product you know inside out and compare Posto's recommendation with your own numbers. The breakdown shows every step.Start 30 days free

What you get

Sold-out days left outDays with nothing to sell aren't counted as zero demand, so a stockout doesn't shrink your next order.
Peaks planned forBlack Friday and the holiday peak, plus each product's recent trend, built into every recommendation.
Stock on order countedPosto never asks you to reorder what's already on the way.
Runway at a glanceEach product shows how long its stock will last next to how long a new order takes, like "Lasts about 11 days · a new order takes 14 days," and flags anything that runs out before a restock can arrive.
Real delivery timesSuppliers quote their best case. Once 3 orders have arrived, Posto times your orders by how long deliveries actually took.

Questions about forecasting

Is Posto's forecast AI?+

No. Posto uses standard inventory math: average daily sales, lead time, and safety stock, with seasonality and trend on top. It's the kind of math you could check in a spreadsheet, and every recommendation shows its working.

How much sales history does Posto need?+

It starts with whatever history you have. Forecasts built on fewer than 8 weeks are marked "Limited history," and seasonality only comes in once there's enough data to trust it.

How does Posto know my supplier lead times?+

You enter each supplier's lead time (how long they take to deliver), or import it from a spreadsheet. Once 3 orders from a supplier have arrived within the past year, Posto switches to the average of how long they actually took and labels it "measured," so you always know where the number came from. If one product takes longer than the rest, give it its own lead time and Posto uses that instead.

Does Posto forecast per location?+

Posto forecasts store-wide, from your sales across all your locations together. You choose which location to receive each purchase order into.

Can I override a recommendation?+

Yes. You can set your own reorder point, service level, or days of cover for any product, and change any quantity before you send an order.

Stop guessing your next reorder

Install Posto, bring your suppliers and costs over, and send your first purchase order. 30 days free, everything unlocked, no payment details.

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