Rat sizes? Help please!

[Skep]

My ball python is around a year and a half old, and he's 6 inches around (circumference)
I've been feeding him two rat weanlings once a week.

However, I need to upgrade his prey size. I'm not sure if I should go with the small rats or the medium rats.
The small rats are 4.50 - 6.00 inches in length (not including tail length) and 45.00 - 84.99 grams each.
The medium rats are 6.00 - 8.00 inches in length (not including tail length) and 85.00 - 174.99 grams each.

I just recently purchased a gram scale to weigh my snake, but I can't weigh him for the next few days, so I'm not sure how much he weighs in grams.

I'm just looking to see if anyone could give me advice on what rat size would be best for him, thank you!

[Eric Alan]

Since you said he, I'd go with small rats. Adult males can get small rats once/week for their entire lives.

[Skep]

Since you said he, I'd go with small rats. Adult males can get small rats once/week for their entire lives.

Alright, thank you.

I'll just wait and see if I get any more advice from other people.

[Saber402]

An easy rule of thumb is 10 - 15% of his body weight, or a prey item that is slightly bigger than the thickest part of his body. Curious as to why you can't weigh for a few days. Did he just eat?

[Skep]

An easy rule of thumb is 10 - 15% of his body weight, or a prey item that is slightly bigger than the thickest part of his body. Curious as to why you can't weigh for a few days. Did he just eat?

Yep, he just ate.

And I need to order the rats pretty soon, do you think the small would be best as well?