Evolv Downsizing

I am looking to get a pair of shamans. I wear a 10 so how far should I downsize for evolv shoes?

I have evolv agros and didn't downsize at all from my street shoe size. I believe that the agros are bassed on the shamans. They hurt for 2 weeks and now they are perfect. I used to wear la sportivas and had to downsize a ton. It seems like evolv run smaller, but they also fit my narrow foot shape better. 

I down sized 1 EU size from my street shoes when I bought my Shamans thinking they would eventually stretch to fit, boy was I wrong. Sold the shoe after 5 climbs cause the shoe didn't stretch at all. I suggest staying with your street shoe in EU sizing. BTW my sizing for reference:

Scarpa Instinct VS: 39.5
Unparallel TN PRO: 40
Evolv Shaman: 40 (should have bought 41)
Street shoes: 41

My street so is 10 and I have a pair of size 10 agro's. I think a 10.5 of the same shoe would honestly be perfect for me, 10 is still unnecessarily painful.

I didn’t end up buying them, but I tried on several pairs and determined that I would need a full size bigger than my running shoe size. 8.5 NB street shoe, 9.5 Shaman. 

I've had three pairs of shaman and get the same size as my street shoe. There true to size.