Replenishment

Reorder point when you do not know your lead time

Every formula treats lead time as a given, and for most importers it is a guess. The real number is recoverable, and the evidence is already in your inbox and in Shopify.

Marcus VolstedCo-founder, Restocio Published 11 September 2026Updated 11 September 20268 min read

Reorder point when you do not know your lead time

You do not need your supplier to tell you the lead time. Two dates you already hold, the day you sent the order and the day the goods became sellable, bracket the whole of it, and three of those pairs are worth more than any quote. Only the source of the formula's most important input changes, from a supplier's estimate of their own punctuality to your own records.

Every reorder point page, ours included, treats lead time as a number ready to copy. For an importer it is a factory, a forwarder, a customs broker and your own receiving bench added end to end, and none of them can quote the total. The reorder point formula and the calculator's in-stock divisor have their own pages. This one is about the input both take on trust.

Where do you find a lead time you never recorded?

In records you already keep for other reasons. Your sent folder dates the order, your bank dates the deposit, your forwarder dates the arrival at port, and Shopify dates the moment the stock went live. Pair a start with an end for the same order and you have a measured lead time, without asking anyone for anything.

Where the date lives	Which end it marks	How far back	Where it goes wrong
The purchase order you emailed	The start	Your sent folder	Nowhere, if it is the version you went ahead with
The deposit on your bank statement	The start, late	As long as your bank keeps them	Reads short by the days spent confirming and paying
Your forwarder's arrival notice	Arrival at port	Inbox or forwarder portal	Reads short, since customs and putaway follow it
Shopify's inventory adjustment history	The day stock became sellable	180 days on the product page, older in a report	Deliveries sit among recounts, so check each line's reason
A purchase order log you start today	Both ends	From today	Only when updated late

The end that matters is the day customers could buy, which makes Shopify your best witness. Its documentation, read on 11 September 2026, sets the limit: "You can view only the last 180 days of inventory adjustment history for a product or variant", with older entries in the Inventory adjustment changes report. Order every couple of months and the product page holds two or three deliveries, so check the report before deciding you have no history.

Both of the easiest dates to find, the deposit and the arrival notice, make the lead time look shorter than it was, which is the one direction you cannot afford.

Which date counts as the start of a lead time?

The day you sent the order. Your reorder deadline tells you when to begin the whole process, so every day after that belongs inside the lead time, including the week the proforma sat unpaid and the days the supplier took to confirm. Starting the clock at the deposit or at the factory's start date quietly deletes them.

At the other end, measure an order that arrives in parts to the last part, not the first box. A delivery that lands 60% on day 70 and the rest on day 95 is a 95-day lead time for whatever came late, and the first date hides the very product you were waiting for.

What do you do on a first order to a new supplier?

You guess, and there is no honest way to dress that up. What you control is which way the guess leans. Take the supplier's quote as the best case, add every segment it does not cover, plan on the total, and write it down with the date so the first delivery turns it into evidence.

A factory quotes production and a forwarder quotes transit. Customs rarely appears on either, and putaway is yours. Ask each party for their own segment only and add them up yourself, using the five segments in the supplier lead time guide.

Read the transit figure as a middle, not a ceiling. Sea-Intelligence's Global Liner Performance report issue 179, read on 11 September 2026, put global schedule reliability at 62.6% in June 2026, with late vessels arriving 5.31 days behind on average. Close to four in ten sailings missed their schedule that month, so a transit quote is a best case with a date on it.

One cheap request makes that first order far more useful. Ask the supplier to email you the day the goods are packed. It costs them one message and splits your first lead time into its factory half and its freight half, so the second order knows which one to argue about.

How much to add on top is judgement, and anyone quoting you a percentage without knowing your lane is guessing on your behalf.

Is it worse to guess your lead time too short or too long?

Too short, by a wide margin. Guess long and you hold some stock earlier than you needed it, which costs storage and cash while every unit stays on the shelf to sell. Guess short and your first warning is an empty shelf, often with only a faster and far dearer shipping route left to fix it.

Here is the mechanism. Safety stock is what you planned to have left when the delivery lands, and every day missing from the lead time is a day of sales that comes straight out of it. Selling 10 a day with a 60-day cushion, a lead time 20 days short spends 200 of the 600 units before anything has gone wrong. Leave out a 45-day production run and three quarters of the cushion goes on every order, even with a supplier who is never late.

Day for day, the costs are lopsided too. A day of extra stock costs a thin slice of what the units are worth. A day of empty shelf costs the margin on every sale that goes elsewhere. The same asymmetry sets how many days of stock to hold.

The two errors also surface differently. Overestimate, and the goods arrive early, so the next measurement shows it and you can trim. Underestimate, and the only signal you get is the stockout.

What does Restocio do when you have no lead time?

It declines to assume zero. Setup asks which routes you use, not how long they take, and a new install starts its delivery time on the slowest route switched on by default, the 70-day sea route. The reasoning is the one above: too large an order costs money you get back, too small costs sales you do not.

From the first order you mark received, the Suppliers page shows how long each supplier really took, per route, beside what your settings assume, without changing any calculation. After three received orders from one supplier inside a year, a gap of a week or more gets a one-click offer in the order dialog to update that supplier's production days.

What is not built is the step after that. Nothing measured writes itself into your settings, and the app does not learn lead times on its own. Until you press the button, the number you typed runs every deadline in the replenishment loop.

The honest gap is production days. They start at zero for every supplier, because we cannot know whether yours ships from stock or makes to order, and setup does not ask. For a made-to-order factory that is the one starting value here that leans short, until you type it on the Suppliers page or three deliveries prompt a suggestion.

Partial deliveries need one more caution. The app dates arrival from the first time an order is marked received, so a split shipment measures to its first part, and the measured figure is then a floor.

Common questions

How do I calculate a reorder point if I do not know my lead time?

Recover the lead time before you touch the formula. The date you sent a past order and the date that delivery went live in Shopify give you one measured lead time, and three from the same supplier beat any quote. With no past orders at all, add the supplier's production quote, the forwarder's transit quote, customs and your own receiving time, then lean the total long.

How can I find my supplier's lead time without asking them?

Use dates you already have. Your sent folder dates the order, and Shopify's inventory adjustment history dates the day the delivery went live, for the last 180 days on the product page and further back in the Inventory adjustment changes report. Avoid starting the clock at the deposit or stopping it at the port arrival notice, because both make the lead time look shorter than it was.

What lead time should I use for a new supplier with no history?

Their quote plus every segment the quote leaves out, rounded up rather than down. A factory quotes production and a forwarder quotes transit, and neither includes customs or the days it takes you to count the goods in. Ask the supplier to tell you the day the goods are packed, so the first delivery shows you how the time actually split.

Is it better to overestimate or underestimate lead time?

Overestimate. A lead time that is too long brings stock in before you strictly need it, which costs storage and tied-up cash while every unit is still there to sell. One that is too short eats your safety stock day for day, and if the gap is larger than your cushion you run out on every order, however reliable the supplier.

What if I only have one or two past orders from a supplier?

Use them, but plan on the slower one rather than the average. One or two deliveries cannot show how much a supplier varies, only that it can take at least that long. Treat the slowest as a floor and let the third delivery tell you whether you were being too careful.

Marcus Volsted

Co-founder, Restocio

Marcus co-founded Restocio and works on it daily with a Swedish importer who plans their purchasing in it every working day. Restocio is built in Sweden by two founders, one Swedish and one Danish, and Marcus is the Danish one. Why we are building it.