# Target and difficulty

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.

Canonical page: https://mybitcoinexplorer.com/learn/target-and-difficulty
Topic: Mining
Published: 2026-10-29
Updated: 2026-10-30


## 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.

> Diagram: Only hashes below the target are valid; most attempts land above it — 

## Difficulty
Difficulty is how many times harder the current target is than the easiest target (the genesis block's):

~~~
difficulty = genesis target ÷ current target
~~~

Difficulty 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](/developers) 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.

## Related lessons

- [Difficulty adjustment](https://mybitcoinexplorer.com/learn/difficulty-adjustment)
- [Proof of work](https://mybitcoinexplorer.com/learn/proof-of-work)
- [The block header](https://mybitcoinexplorer.com/learn/block-header)
- [Hashrate](https://mybitcoinexplorer.com/learn/hashrate)