What day should the reorder reminder go out?
Enter how long one pack lasts, your shipping time and the buffer you want. See the day after delivery to send the reminder, and how that day moves with bigger or smaller packs.
- 4 inputs
- 1 open formula
- No sign-up
One pack, one reminder day.
Type your own numbers. The reminder day updates as you go.
Your product
Filled in with an example: a 250 g bag of coffee, 12 g a day, 2 days of shipping and 3 days of buffer. Replace it with your own numbers.
Any unit: grams, millilitres, capsules. Use the same unit for daily use.
What one customer uses on a normal day. For weekly use, divide by 7.
From your own experience, a product page or customer reviews.
Days from order to delivery.
Days of product that should be left when the new pack arrives.
- One pack lasts
- 20.8 days
- New pack arrives
- day 17
- Left when it arrives
- 3.8 days
- Day 0 Delivered
- Day 15 Reminder
- Day 17 New pack arrives
- Day 20.8 Pack runs out
- Using the pack
- Reorder on its way
- Buffer left
Assumes the customer orders on the day the reminder arrives.
| Pack | Lasts | Reminder | From order |
|---|---|---|---|
| ½×125 | 10.4 | 5 | 7 |
| 1×250yours | 20.8 | 15 | 17 |
| 2×500 | 41.7 | 36 | 38 |
| 3×750 | 62.5 | 57 | 59 |
| 4×1,000 | 83.3 | 78 | 80 |
In days. The reminder day counts from delivery, the last column from the order. A bigger pack, or two packs per order, pushes the reminder out.
This day fits a customer who uses the pack at exactly the pace you entered. Say one customer goes through it a quarter faster and another a quarter slower. The first needs the reminder on day 11, the second on day 22. One fixed day is early for one of them and late for the other.
Oftenflow learns each customer’s own rhythm from their orders and proposes the reminder when it’s due for them. How buying rhythm works →
A starting point from the numbers you entered. Real use differs per customer, so check it against your orders: the median time between orders for this product shows the real pace.
A reminder day per customer.
Oftenflow is an AI agent for Shopify stores, still in development. It learns each customer’s interval per product from their orders, corrected for quantity, and proposes the reminder when it’s due.
You approve, your own email tool sends.
How buying rhythm works →Planned: 30% off for the first 100 stores. One email when your invite is ready, no newsletter.
Three numbers, one subtraction.
The calculator works out how long one pack lasts, then counts back the shipping time and the buffer you want. What’s left is the day to send the reminder.
- one pack lasts
- = pack size ÷ use per day, or the days you entered
- reminder day
- = one pack lasts − shipping time − buffer, rounded down
- day after the order
- = reminder day + shipping time
- new pack arrives
- = reminder day + shipping time, counted from delivery
- left on arrival
- = one pack lasts − the day the new pack arrives
In plain language
- Day 0 is the day the pack is delivered. The customer starts using it that day.
- A 250 g bag at 12 g a day lasts 250 ÷ 12 = 20.8 days.
- A reorder takes as long to arrive as the first order did, so we take off the shipping time: 2 days.
- You want some product left when the new pack lands, so we take off the buffer too: 20.8 − 2 − 3 = 15.8.
- We round down to day 15, so the new pack arrives with at least the buffer left. Rounding up would eat into it.
- If your email flow counts from the order date, add the shipping time: day 17 after the order.
- The table repeats this for half, double, three and four times the pack, because a bigger pack or two packs per order push the reminder out.
What this leaves out
- Customers who use more or less than you entered. The note in the calculator shows how far a quarter faster or slower moves the day.
- Time between the reminder and the order. If customers tend to wait a few days, add those days to the buffer.
- Packs that get shared, stocked up or forgotten in a cupboard. Real orders show this; a formula can’t.
- Weekends and holidays in shipping, and emails that get opened a day late.
- Customers who reorder before the reminder day. Leave them out of the send.
- Your order history. Once a product has enough repeat orders, the median time between orders is a better starting point than this formula.
Questions about reminder timing
When should I send a reorder reminder?
A few days before the customer runs out, minus the time a reorder takes to arrive. This calculator works that out from pack size, daily use, shipping time and a buffer. Once you have repeat orders for the product, use each customer’s own median time between orders instead.
Should I count from the order date or the delivery date?
The customer starts using the pack when it arrives, so the calculator counts from delivery. If your email flow starts at the order, add the shipping time. The calculator shows both days.
How big should the buffer be?
Think about what happens when the pack runs out. For coffee it’s an annoyance. For pet food it’s a trip to the supermarket, and the sale goes there. Allow for a late delivery and for a customer who waits a day or two before ordering.
What if customers buy two packs at once?
Then they come back about twice as late. Use the 2× row in the table, or enter the total amount per order as the pack size. Our guide on time between orders shows how to correct for quantity with real orders.
Why not send every customer the reminder on the same day?
Customers use products at different speeds. The calculator gives the right day for the pace you enter. A customer who goes through the pack faster runs out before that day, and a slower one gets the reminder too early. Timing per customer, from their own orders, fixes both.
Get an invite when we open the doors.
Planned: 30% off for the first 100 stores. One email when your invite is ready, no newsletter.
- Plans from €29 a month, never per contact
- Works with the email tool you already use
- No card, no commitment
