I made this blog to calucate some of Thor's greatest speed feats, i hope the blog will help.
Mjolnir to the edge of the Galaxy[]
The Milky Way is around 150,000 light years. Mjolnir did it in one minute and came back. 150,000 Light years is 1.419110e+18km. 1.419110e+18km in one minute is 78,894,001,340 times the speed of light.
Thor crossing the Universe[]
I'll give a time frame of one minute for the low-end and 5 seconds for the high end. 94,000,000,000 light years is 8.893087e+23km. 8.893087e+23km in one minute is 4.94402278678E+16, which is 49 quadrillion times the speed of light. For the high end, 8.893087e+23km in 5 seconds is 5.932e+17c which is 593 quadrillion times the speed of light.
NOTE: It took serveal panels for Thor to cross the Universe, so the low end is likely more accurate.
To the End of the Universe[]
So, Thor reached to the End of the Universe after flying from Asgard. Since each Realm is a Universe, Thor should have cover 188 billion light years in a short time frame. Why 188 billion LY? Because he flew from a realm (A Univere) to the End of the Universe. 188 billion light years is 1.778617e+24km. The time frame for a low-end is one minute and one seconds for a high end. 1.778617e+24km in one minute is 9.8880433498E+16c which is 98 quadrillion times the speed of light. 1.778617e+24km in one second is 5.93282600988E+18, which is 5 quintillion times the speed of light.
Mjolnir crossing the Realms[]
Mjolnir crossed the nine realms which are Universes. 94X9 is 846, so Mjolnir crossed 846 billion light years. 846 Billion light years is 8.003778e+24km. Low End is 10 minutes, Mid-End is one minute and high end is 5 seconds (It took serveal panels for Mjolnir to cross the Realms so 1 sec for high end is highly unlikely)
8.003778e+24km in 10 minutes is 44.4 quadrillion times the speed of light
8.003778e+24km in one minute is 444 quadrillion times the speed of light
8.003778e+24km in one sec is 26 quintillon times the speed of light
MFTL+
Notes[]
This blog is low-ball and outdated. The Marvel Universe size is actually around trillions of light-years, and there are many theories that the Universe is actually sextillions of times greater, which would give us a much larger number than just 94,000,000,000 LY. Thor's finite top speed would scale anyway to 7.213609197e44 which is 2 Undecillion c, and his fastest speed feat is immeasurable anyway.