Alan couzens has a submax effort vo2max calculator on his website. There was a thread on here last week about it. I put a bunch of my 100/100 runs into it, and got very consistent results across a wide range of efforts.....from z1/z2 (8:30pace) efforts up to fast mile (5:50 pace) repeats. So, for me it was pretty spot on.

Eta: here's the link:

https://alancouzens.com/blog/VO2Scores.html

I'd put your numbers into that and work forward from there using Daniel's formulas.

Had brunch with the family... Gonna go do my bike ride as a warmup and then give the 5k a go.

However, I did a double yesterday for a total of 10miles. That might not have been the best taper strategy for a 5k race today. So, I've got my excuse lined up already. :=)