Block Height
The sequential number of a block in the Bitcoin blockchain, counting from the genesis block (block 0). Used to track chain progress.
What is Block Height?
Block height is the sequential number assigned to each block in the Bitcoin blockchain. The first block ever mined (the genesis block, created by Satoshi Nakamoto on January 3, 2009) is block 0. Each subsequent block increments the height by one. The current block height tells you exactly how many blocks have been added to the chain since Bitcoin's creation.
Why Block Height Matters
Block height serves as Bitcoin's universal clock. Rather than using timestamps (which can be imprecise), the Bitcoin protocol uses block height to schedule critical events:
- Halving: Occurs every 210,000 blocks (the most recent at block 840,000 in April 2024)
- Difficulty adjustment: Recalculates every 2,016 blocks
- Soft fork activations: Protocol upgrades activate at specific block heights
Because blocks are found approximately every 10 minutes, block height also provides a rough time estimate. Block 840,000 at 10 minutes per block represents approximately 16 years of mining since the genesis block.
Block Height and Halving Countdown
One of the most practical uses of block height for miners is tracking progress toward the next halving. Since each halving cuts the block subsidy in half, miners closely monitor how many blocks remain until the next halving event. The next halving will occur at block 1,050,000, which is estimated to happen in 2028.
Current Block Height
The Bitcoin blockchain adds roughly 144 blocks per day (one every ~10 minutes). You can check the current block height on any block explorer or through the network statistics displayed on mining pool dashboards. The block height is constantly increasing and serves as an immutable record of Bitcoin's entire transaction history.