**TL;DR** You’d have less than bupkis.

I am in the middle of writing my undergrad thesis. (Thank god I’m finally graduating.) It’s about a particular social aspect of the network of computers used to maintain the Bitcoin to Paypal conversion network and instant bitcoin exchange platforms.

In a moment of distraction, I decided to compute the amount of time it would take to mine a Bitcoin block by hand at today’s network hashrate.

Here are the assumptions:

- The network hashrate remains constant.
- The miner, in this case, is Ken Sherriff and he’s able to crank out hashes at a constant rate of .67 hashes per day with a pencil and paper.
- I assume a perfectly fair network, in which blocks are mined exactly proportionally to the share of network hashrate. (i.e. if one had 1% of the network, one would expect to mine 1% of the blocks)
- I also assume that Ken is able to broadcast his correct hash to the network just in time.

At the time of writing, the Bitcoin network hashrate is somewhere around 827,236,336 GH/s.

Let’s do some arithmetic!

- The total network capacity is 827,263,336
*billion*hashes per second. Written with lots of zeroes, that’s 827,263,336,000,000,000 hashes per second. - Ken’s rate of .67 hashes per day converts to 7.75×10^-6 hashes per second
- If Ken started mining today, his share of the network would be 9.36824*10^-24.
- This means that Ken would get the right hash once every 9.638*10^24 blocks.

- Since there are 144 blocks per day, Ken would find a block once every 6.50572*10^22 days, which converts to once every 1.78239*10^20 years.
- The universe is ~1.4×10^10 average Gregorian years old.
- It would take 1.27314*10^10 times the current age of the universe for Ken to find one block by pencil and paper.

That was fun, wasn’t it?