Calculating share difficulty required to solve a block

Hey, so I'm sure you've seen the share difficulty roll by in your miner on your command prompt… like, 5.49 G, 294 G, 1.55 T, etc. I've been wondering what share difficulty would be required to be a block solution. I couldn't find any answers to this, so I tried to derive an equation for it. I am looking for someone to tell me if I'm right or wrong in this. I am not saying I'm right, just that this is how I think it works, and if someone could correct me I'd appreciate it.

First, I'll start with 2 basic formulas I know.

• Time to solve a block in minutes = Network hashrate / Local Hashrate
• Seconds per share = Share Difficulty / Local Hashrate

So, if I have 525 MH/s, my time to solve a block in minutes with a difficulty of 10.43 TH is 10.43 TH / 525 MH, or 10,430,000 MH / 525 MH, 19,866 minutes, or 1,191,960 seconds.

If I'm mining to a pool with 4.29g difficulty (2 miners for example) the expected number of seconds to mine a share would be 4290 MH / 520 MH, or 8.17 seconds per share. I don't care about a 4.29g difficulty share though, I want to know the difficulty of a share that would solve a block. So, I want to know the difficulty of a share that would take 1,191,960 seconds. So then, we get:

• 1,191,960 = X / 525 MH

Solved for X, we get 625,779,000 MH, or 625 T.

Trying to come up with a more generic solution then, I think I can do this:

• Local Hashrate = A
• Network Hashrate = B
• Share Difficulty = X

• Seconds to solve a block = B/A * 60

• A * ( B/A * 60) = X

• A * 60B/A = X

• 60B = X

So… 60 just happens to be the block time of Ravencoin, so then that makes the equation for the difficulty of a share required to solve a block:

• Network Hashrate * Block Time = Share Difficulty

So if the network hashrate is 10.43 TH, the share difficulty required to solve a block is

• 10.43 TH * 60 = 625.8 TH.

If someone can check my work, I'd appreciate it. Thanks. This might be common knowledge, but I couldn't find an answer for this anywhere else.