Here's the numbers we know:


- Our universe's diameter = 93 billion light years (approximately 8,8 * 10^23 km)
- Multiverse biggest map volume = 47 104 universes (not galaxies, UNIVERSES) also a sphere like our universe


Now to calculate the size:


Our universe volume = (4 / 3) * pi (using calculator with pi itself) * r^3 (half of diameter to the power of 3) = (4 / 3) * pi * (4,4 * 10^23)^3 = 3,6 * 10^71 km^3


Now since the final universe volume is in km^3, we can just multiply that by 47 104 which gives us
Multiverse volume = (3,6 * 10^71) * 47 104 = 1,7 * 10^76+ km^3
NOTE: The + is because there is extra space between every universe inside the multiverse according to the mapmaker.


That's 17 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000+ km^3!


Or in lightyears^3, as 1 lightyear^3 = 8,5 * 10^38 km^3 then ---> (1,7 * 10^76) / (8,5 * 10^38) = 2 * 10^37+ lightyears^3
= 20 000 000 000 000 000 000 000 000 000 000 000 000+ lightyears^3.


As for how long it will take to travel from one side to the other we will need to find the diameter of the multiverse.
For that we can change the formula of volume from V = (4 / 3) * pi * r^3 to r = 3rdRoot((3 * V) / (4 * pi))
The radius is then r = 3rdRoot((3 * 2 * 10^37) / (4 * pi)) = 1,7 * 10^12+ lightyears
Multiply by 2 as radius is half of diameter we get (1,7 * 10^12) * 2 = 3,4 * 10^12+ lightyears wide


If you travel at the speed of light, you will have to travel for 3,4 * 10^12 earth years to get from one side to the other (because 1 lightyear is the distance light travels for 1 year)
or 3 400 000 000 000+ earth years.
For reference the earth is 4 800 000 000 000 years old, you would have to travel at light speed for near all of earth's lifetime to get to the other side. 708 times more than earths lifetime.


Open to discussion if some numbers seem off or if i did some calculations wrong

edit: I see something is wrong here about the time to travel, if the universe is 93 billion lightyears wide it doesn't make sense to be able to travel this multiverse in just 3,4 billion years
edit again: im dumb i just wrote earths age as 4,8 trillion not billion