The target is the number a block hash must be below; difficulty says how much harder that is than the first target. Learn how both are calculated.
The target
Think of every possible hash as a number from 0 to an enormous maximum. The target is a line on that range: the block hash must fall below it. A lower target means fewer winning hashes, so it takes more tries.
Difficulty
Difficulty is how many times harder the current target is than the easiest target (the genesis block's):
difficulty = genesis target ÷ current targetDifficulty 1 was the start in 2009. Today it is in the trillions.
Bits
The header stores the target compactly in 4 bytes called bits. For example 1d00ffff means 0x00ffff × 256^(0x1d − 3), which is the genesis target.
Expected tries
On average, finding a block takes about difficulty × 2^32 hashes. At difficulty 1 that's about 4.3 billion. Today it's more than 10^22.
Difficulty in numbers
Difficulty started at 1 in 2009. In late 2026 our node reported about 148 trillion, meaning each block takes roughly that many times the work of the first blocks. MyBitcoinExplorer's block API returns the exact difficulty for every block.
Why a target and not "number of zeros"?
"Leading zeros" only allows difficulty to jump in steps of 16. A numeric target lets the network adjust smoothly, by a few percent at a time.
Key takeaways
- A block hash must be numerically below the target.
- Difficulty compares the current target with the genesis target.
- The header stores the target in the compact bits field.
Common questions
Who sets the difficulty?
Nobody. Every node calculates it from the timestamps of past blocks, using the same formula.
Why does a lower target mean more leading zeros?
Smaller numbers written in fixed-width hex begin with more zeros.
What is the current Bitcoin difficulty?
It changes every 2,016 blocks. In late 2026 it was about 148 trillion; any block's exact value is available through our block API.
Is higher difficulty good?
It means more hash power is securing the network, which makes attacks more expensive.