Here's how we calculate it. We take the total fuel-ups divided by the number of weeks you've been fueling. In your case you have 81 fuel-ups over the course of 146 weeks which gives us 0.554 fuel-ups per week. We round that up which gives us an average of 1 per week.
I see the confusion, ZilogJones. In reality there's only 33 days between your first fuel-up and your last fuel-up. So in our system a "month" is 30 days. But you're expecting each *change* in calendar month to represent a month in our system.
Yeah, that is confusing if you're thinking of calendar months instead month as a general 30-day timespan. We might need to change the wording there or change how things are calculated. I'll give it some thought.
KeithUK, sounds like you're talking about Fuelly badges. Here's a direct link to your badge image. I see 17 fuel-ups listed. You might have a locally cached version of the image in your browser. Try clicking the link here and then a refresh at the URL once it's loaded.
If you're looking for the page that lists the badges, you can find a link under the Log Book. There's a picture of the badge icon in this FAQ, list item #4.
If you have the sidebar expanded, there's also a sample badge on the right hand side of the page when you're viewing your vehicle profile page.