Short answer: in a café, 8 or 10 stamps for a free coffee is the norm. If your customer comes almost every day, 10 or 12 stop them filling the card too quickly; if they come once or twice a week, 6 or 8 gets them to the reward within a couple of months. What matters is that the card can be filled in a time frame the customer sees as achievable, not the number itself.
There's no magic number: the same number of stamps works very differently depending on how often people come in. A 10-stamp card is filled in two weeks by someone who has breakfast with you daily; for someone who comes on Saturdays, it takes ten.
This guide gives you a way to work it out with your own customers. For the general rule for any business, first read how many stamps a loyalty card should have.
The formula in one line
Stamps = target time frame in days ÷ days between visits.
Decide how long you want it to take your regular to fill the card (for coffee, a month is a good starting point) and divide by how many days usually pass between visits. If the time frame is 30 days and they come every 4 days, that's 7.5, so about 8 stamps. Then check that the reward doesn't cost you more than you want to invest.
A shift-by-shift example: three types of customer in the same café
Imagine a neighbourhood café with three types of customer. The numbers are illustrative, to show how the maths works; yours will be different.
| Customer | When they come | Visits per month | With 8 stamps | With 10 stamps |
|---|---|---|---|---|
| The every-morning regular (breakfast) | Monday to Friday | 20 | About 2 weeks | 2 weeks |
| The mid-morning or lunchtime customer | 2 or 3 times a week | 8 a 12 | 3 to 4 weeks | 3 to 5 weeks |
| The afternoon or weekend customer | Once a week | 4 | 8 weeks | 10 weeks |
(The maths: 8 stamps ÷ 5 visits a week is about 1.6 weeks; 8 ÷ 3 is about 2.7 weeks and 8 ÷ 2 is 4; 8 ÷ 1 is 8 weeks. With 10 stamps: 2, 3.3 to 5, and 10 weeks.)
What it shows: with 10 stamps, the every-morning regular gets a free coffee every two weeks; the weekend customer takes ten. One card can't be perfect for all three. You have three options:
- Set the card around the customer who matters most to you (usually the weekday regular) and accept that the weekend customer will take longer.
- A welcome stamp. Give a stamp when they save the card so nobody starts from zero. With a 10-stamp card, the weekend customer is already on 1 of 10 on day one.
- A daily-use rule. If you don't want someone who comes twice a day to fill the card too fast, set your own rule (for example, one stamp per day) and put it on the poster.
What counts as a stamp?
The clearest is one stamp per visit, not per coffee or per euro. If someone orders three coffees for their team, that's one visit. If you want to reward spend, it's no longer a stamp card but a points card: see points card or stamp card. Choose a simple rule and don't change it every month.
What the reward costs you
Always calculate with the product cost, not the selling price. An illustrative example with made-up numbers: a €1.50 coffee that costs you €0.30 in product.
With a 10-stamp card, the customer spends €15 and you give away a coffee that costs €0.30: 2% (0.30 ÷ 15 = 0.02). With 8 stamps, the reward is 2.5% (0.30 ÷ 12). Do the same maths with your prices. If the reward is a coffee and toast, use the cost of both.
What changes with a digital card
With paper, the customer loses or forgets the card and you don't know how many are halfway there. With a digital card saved on the phone (Apple Wallet or Google Wallet), the customer has nothing to carry and you see in the dashboard how many cards are close to the reward.
If you see that hardly anyone gets there, you adjust the number of stamps or change the reward for new customers. The details are in digital stamp card and the version designed for your business in loyalty card for cafés.
Common mistakes with coffee stamps
- Too many stamps. If the reward is so far away the customer thinks it's impossible, they don't start.
- Too few. A free coffee on the third visit eats into your margin.
- Rules that change. If it's one stamp per coffee one day and one per visit the next, you lose trust.
- An unappealing reward. A simple free coffee works; something the customer doesn't value doesn't.
- Not measuring. Every month, check how many saved the card, how many came back and how many redeemed; adjust based on that.
Frequently asked questions
How many stamps should a coffee card have?
8 to 10 is the norm. If the customer comes every day, 10 or 12; if they come a couple of times a week, 8 usually gets filled in a month.
Is one stamp per coffee or per visit better?
Per visit. It's easier to explain and stops a big order filling half the card in one go.
Can I give a stamp when they save the card?
Yes, it's a common trick so nobody starts from zero and they're encouraged to come back.
Sources
The numbers in the examples are illustrative and made up to show the calculation; they aren't results from any business. The formula and arithmetic are our own.
