# Block height

Block height is a block's position in the chain, counting from 0 at the genesis block. Learn how heights schedule halvings, timelocks and confirmations.

Canonical page: https://mybitcoinexplorer.com/learn/block-height
Topic: Blocks and the blockchain
Published: 2026-10-29
Updated: 2026-10-30


## Counting from zero
Height is simply how many blocks come before a block. The [The genesis block](https://mybitcoinexplorer.com/learn/genesis-block) is height 0, the next is height 1, and so on.

> Diagram: Height counts blocks from the genesis block — Height 0,Height 1,Height 2,Height 3

## Why heights are useful
- **A simple clock.** Bitcoin uses heights to schedule events: the [halving](https://mybitcoinexplorer.com/learn/bitcoin-halving) happens every 210,000 blocks, [Difficulty adjustment](https://mybitcoinexplorer.com/learn/difficulty-adjustment) every 2,016.
- **Timelocks.** A [locktime](https://mybitcoinexplorer.com/learn/locktime-and-sequence) below 500,000,000 is a block height.
- **Confirmations.** Confirmations = current tip height − block height + 1.

## Height isn't unique, a hash is
For a short time two blocks can share the same height (a [fork](https://mybitcoinexplorer.com/learn/stale-blocks-and-reorgs)). The block **hash** is the true unique ID; height is a convenient position.

> Interactive exercise: [open the lesson](https://mybitcoinexplorer.com/learn/block-height).

## Famous heights
| Height | What happened |
|---|---|
| 0 | [Genesis block](/block/0) |
| 170 | [First person-to-person transaction](/block/170) |
| 210,000 | [First halving](/block/210000) |
| 481,824 | [SegWit activated](/block/481824) |
| 709,632 | Taproot activated |
| 840,000 | Fourth halving |


## Look up any height
Type a number into MyBitcoinExplorer's [search](/explorer) to open that block: for example [840,000](/block/840000), the 2024 halving, or [0](/block/0), the genesis block.

## Height and time
At about 144 blocks per day, you can estimate when a future height arrives: 52,560 blocks is roughly one year. Because block times vary, such estimates can drift by days.


## Key takeaways

- Height is a block's position in the chain, starting at 0.
- Bitcoin schedules halvings and difficulty changes by height.
- The hash, not the height, uniquely identifies a block.

## Common questions

### What is the current block height?

It grows by about 144 per day. Our status page shows the height our node has verified.

### Is block height stored in the block?

Not in the header, but since BIP 34 it must be written at the start of the coinbase transaction.

### What is the current Bitcoin block height?

It grows by about 144 blocks a day. Our homepage and status page show the latest height our node has verified.

### What is the difference between height and depth?

Height counts from the genesis block; depth (confirmations) counts back from the latest block.

## Related lessons

- [What is a block?](https://mybitcoinexplorer.com/learn/what-is-a-block)
- [Stale blocks and chain reorganizations](https://mybitcoinexplorer.com/learn/stale-blocks-and-reorgs)
- [The Bitcoin halving](https://mybitcoinexplorer.com/learn/bitcoin-halving)
- [Locktime and sequence](https://mybitcoinexplorer.com/learn/locktime-and-sequence)