# How calculate mining hash rate from JUST difficulty and change in block creation times?

How calculate mining hash rate (H) from just difficulty (D) and change in block creation times (ΔT) ?

I think

H = ΔT / D

but I'm having trouble confirming that.

Part of the difficulty is that the values fluctuate so much that if different people take different averages they'll get different answers.

Take block 4,000,000 (4M) as an example...

D = 1,096,303,811,407,388 ΔT = 4 seconds between block #(4M + 1) and block #4M

So H = 4 / 1,096,303,811,407,388 = 3.6E-15 ?

I think you mean:

`D = H * ΔT`

In which case:

`H = D / ΔT`

Which gives you:

`1,096,303,811,407,388 / 4` => `274,075,952,851,847`

Or 274,075.95 GH/s (Or thereabouts. It looks in the right ball park.)

• I am surprised this isn't documented anywhere. I can't find it in the yellow paper or anywhere else. All I found was a comment in yellow paper on page 6 that "the expected time to find a solution is proportional to the difficulty". Commented Jan 26, 2018 at 20:12
• Actually, it looks like answer is in yellow paper on right side of page 6 if I can slog thru the details. Commented Jan 27, 2018 at 2:15