How do I split utility with my roommate (soon to be roommates)

The rent payment is automatically taken out of our accounts. So we don't really factor that into the cost. I just put it down to help keep cost of my spending for the month.

But the real question is the utilities. Obvious things like heating/gas bill are gonna be split evenly since we live in the same house and share the exact same space. So we are trying to do a genuine 50/50 split of all the bills.

Does this look right?

D is me R is roommate.
In theory, since I paid 170.44 for my share of the utilities.
and they paid 83.99 for theirs.
The difference between the two bills is 86.45. They said, they owe me 86.45 for the month.

But I said, don't you mean 43.23 (we rounded up) because if we are splitting the costs evenly despite me paying more in the total between the two, They use the internet and heat just as much as me, so it should be halved ?

I am not going to argue with getting more money, but at the same time it feels wrong if the math is wrong and I don't want to take advantage of my roommate. They are kind and the last thing I wanna be is the asshole who can't be trusted since this is my first time having roommates.

|| || |R&D’s monthly bills|Month 1| |Internet (D)|81.23| |Gas/heat (D)|89.21| |Electric ®|83.99| |Rent (D)|1197.5| |Rent ®|1197.5| ||| ||| ||| |Total cost (personal tracker)|2649.43| |Total monthly utility bill of (D)|170.44| |Total monthly utility bill of ®|83.99| |Combined cost of utilities|254.43| |Bill split for utilities(D)-®|43.225| |(If negative (D) owes ® if positive ® owes (D)||