Why would it be good to show number of items in basket in addition to total price?

Question

There is usually a basket area on ecommerce websites - located op top right corner of the page. It's usually a basket/cart icon, sometimes with additional information. Customer asked us to add number of items in the basket there. Why does it make sense to display number of items in addition to the total price, that's already there?

In my oppinion it's confusing, because it's hard to display the number that customer is expecting. If you're buying one product it's 1, that's ok. If you're buying 3 pieces of one product, you would expect to see "3 items in basket". If you're is buying 3 different products you would expect to see "3 items" as well. But it would be unexpected to see "you have 5 items" if you had 3pcs and 2pcs (I would expect "2 items").

Generally I don't see much use of displaying number of items in addition to the total amount anyway. Most important information for me is whether it's empty or if there is something there. If I need to know more I go to the basket page.

What do you think?

Update: The request from our clients come through designers. Practically. The designer designed the cart with number of items, so we want number of items. Sometimes there is no price, only number of items. So at least sometimes it's not decision-driven, it's just because the designer drawn it so... Also: Biggest and (IMO) best czech ecommerce website Alza.cz (https://www.alzashop.com/, https://www.alza.de/) does not have it. Amazon shows only the number of items, not price.

Answer 1

Based purely on your question, why is it difficult for you to show two items and in brackets show the number of pieces per item? If nothing else, there are two reasons that the user might want to see this (not saying that they will, but it is not good to make design assumptions/decisions without checking with users these days):

1. To make sure that they have made the correct purchase even before they hit the checkout area.
2. To keep track of purchase as they continue to shop on the site.

You'll probably notice that all the answers in UXSE tends to be driven by the context (both users and application), so there is no right or wrong answer as such.

Answer 2

Having the number of items in a cart is good practice.

• From a design perspective, the number of items provides:
  • A form of feedback to confirm to users that item(s) have been added to the cart.
  • A visual indicator of what is in the cart. Don't underestimate this because "it's just a number". It's well studied that even basic indicators can help users feel more in control and informed during a session.
  • A subtle cue to action. The vast majority of shopping cart are abandoned and for various behavioral reasons, users will often start the checkout process (or at least review a cart) once the items in the cart reach a certain number.

The benefits of shopping cart indicators and design are pretty well studied. This article provides a decent overview and also some data and commentary around showing the number of items.

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For your case...

This is a feature that can be A/B tested very successfully because it's well encapsulated. So if you're considering it I would highly recommend testing it.

I'll note that leading e-commerce companies that perform extensive testing do usually end up showing the number of items in the cart.

It's more typical to have the total number of items shown in the cart, just like one would estimate total items in a real life cart. So if you have 5 apples and 3 oranges, the number 8 would be shown.