Block Reward

💡 The Plain-English Definition

The block reward is the total payment a miner receives for successfully adding a new block to the blockchain. It comes in two parts: newly created bitcoin (called the subsidy) and the transaction fees from all the transactions in that block.

🤔 But Why Though?

Someone has to do the work of validating transactions and packaging them into blocks. Bitcoin’s answer to “why would anyone bother?” is the block reward — a direct financial incentive, paid automatically by the protocol to whoever wins the proof-of-work race for each block.

The two-part structure is deliberate. The subsidy — the new bitcoin — provides the early incentive during Bitcoin’s first decades, when transaction volume is still growing and fees alone wouldn’t attract serious mining. Bitcoin began with a subsidy of 50 BTC per block, when Satoshi mined the genesis block (the very first block) in January 2009. Every 210,000 blocks — roughly every four years — this subsidy halves: 50 → 25 → 12.5 → 6.25 → 3.125 BTC. After the April 2024 halving, it sits at 3.125 BTC per block.

The halving continues until the subsidy reaches effectively zero around the year 2140, when the last fraction of a satoshi — the smallest unit of bitcoin, one hundred-millionth of a coin — is mined and the full 21 million supply is complete.

Transaction fees, paid by users who want their transactions included, are the long-term revenue that will have to sustain mining once the subsidy is gone. For now the subsidy vastly dominates: fees typically make up 5–20% of total block rewards, with spikes during busy periods. Whether the shift to fee-based security can keep mining strong enough is Bitcoin’s most important unresolved long-term question.

🌍 The Real-World Analogy

Think of the block reward like a government grant for building roads, combined with ongoing toll revenue from the drivers who use them. In the early years the grant does most of the work — road builders wouldn’t bother for tolls alone when traffic is sparse. As traffic grows and the grant shrinks, toll revenue increasingly carries the network. Bitcoin’s block reward follows the same arc: subsidy-heavy now, fee-heavy eventually.