Network Difficulty

It is a target, not a measurement

Mining a block means finding a hash below a threshold. Difficulty sets that threshold. A difficulty of 1.85 PH means the network expects roughly 1.85e+15 hash attempts before one succeeds. Nobody chooses this number directly — the protocol adjusts it.

It adjusts every block

ETC retunes difficulty on every block rather than on a fixed schedule. If blocks are arriving faster than the target, difficulty rises; if slower, it falls. This is why block time stays near its target while hashrate moves freely, and why a hashrate spike shows up as a difficulty rise a short time later.

Hashrate is derived from it

Network hashrate cannot be measured directly — no one can count the hashes every miner tries. It is inferred: difficulty divided by average block time. That is why the hashrate figure on this site moves with difficulty, and why the two charts share a shape.

How network hashrate is calculated

What it means if you mine

Your share of block rewards is your hashrate divided by the network's. Rising difficulty at a constant block reward means the same hardware earns less ETC per day. Difficulty is therefore the variable that moves mining revenue between fifthings, when the block reward itself is fixed.

Estimate earnings at current difficulty

Difficulty and security

Difficulty is the direct cost of rewriting history. Reorganizing the chain means redoing the accumulated work of every block being replaced, so a higher sustained difficulty raises the price of an attack in proportion.