Bitcoin is a payment network with a fixed supply. Miners secure it with proof-of-work, and it adds a block about every 10 minutes on average. The total will stop just under 21 million coins. Ethereum is a platform for smart contracts and applications. Validators have secured it with proof-of-stake since September 15, 2022. It creates a block every 12 seconds, and ETH has no fixed supply cap: new ETH goes to validators and part of every fee is burned.
Purpose: money versus a programmable platform
Bitcoin's own FAQ describes a currency network. It says "only 21 million bitcoins will ever be created" and that the issuance schedule is fixed in the protocol. It does not describe the network as a place to run general applications.
Ethereum's documentation presents ETH as the asset that runs the network. Every transaction pays a fee in ETH, and the fee depends on the computation used (gas) and on demand. Validators stake ETH to secure the chain and earn rewards for it. That fee and staking design exists because Ethereum runs code. Developers deploy smart contracts, and decentralized finance and NFT applications run on top of them. The contract mechanics are covered in how Ethereum smart contracts work.
Verification: proof-of-work versus proof-of-stake
Bitcoin
According to the Bitcoin developer guide, "each block prove a significant amount of work was invested in its creation." A miner proves that work by producing a hash of the block header that falls below a target value. Every 2,016 blocks the network measures how long the last period took against a two-week target and resets the difficulty. That adjustment holds the average near 10 minutes per block. Bitcoin's FAQ adds that discovery is irregular: "there is no guaranteed minimum or maximum delay." Six confirmations are commonly treated as safe for a payment. A payment's route from signature to block is traced in how a Bitcoin transaction is signed, broadcast and confirmed.
Ethereum
The Merge on September 15, 2022 joined the original Ethereum Mainnet to the Beacon Chain, a separate proof-of-stake chain. In ethereum.org's words, "proof-of-work was permanently replaced by proof-of-stake". A validator must deposit 32 ETH into the deposit contract. Validators who act dishonestly can lose part of their stake through slashing, for example by proposing two blocks in one slot or signing contradictory attestations. In a mass slashing event the loss can reach 100% of the stake. Once a block is finalized, it cannot be reverted without a majority of stakers being slashed.
Energy use
On its Merge page, ethereum.org says the switch cut energy consumption by about 99.95%. Its energy page quotes a higher estimate from the Crypto Carbon Ratings Institute (CCRI): annualized electricity use fell by more than 99.988%. Both figures come from ethereum.org. They differ because they are separate estimates.
How far away is the next Bitcoin halving?
Enter the current Bitcoin block height to estimate how many days remain until the subsidy halves at block 1,050,000, assuming blocks arrive about every 10 minutes.
| Current Bitcoin block height | Estimated days until the halving to 1.5625 BTC |
|---|---|
| 972,985 | 535 days |
| 972,985 | 535 days |
| 840,000 | 1,458 days |
- The estimate uses 144 blocks a day, the rate that follows from an average of about 10 minutes per block.
- Bitcoin block discovery is irregular, with no guaranteed minimum or maximum delay, so the real date can come earlier or later than the estimate.
This counts blocks only: it cannot predict actual block times, which vary around the 10-minute average, and it says nothing about price, fees or Ethereum's supply.
Block time: 10 minutes versus 12 seconds
| Bitcoin | Ethereum | |
|---|---|---|
| Interval | About 10 minutes on average (bitcoin.org) | One slot every 12 seconds (ethereum.org) |
| How it is kept | Difficulty reset every 2,016 blocks | Fixed slot schedule; 32 slots make one epoch |
| Variation | Irregular; no minimum or maximum delay | A slot can stay empty if the chosen validator is offline |
Some explainers give Ethereum's block time as about 15 seconds, a figure from the proof-of-work era, when block times were probabilistic and set by mining difficulty. Ethereum's documentation now gives 12 seconds. An empty slot makes the gap between two blocks longer than 12 seconds, but the schedule does not change.
Supply: a hard cap versus net issuance
Bitcoin
- Cap: The Bitcoin Wiki puts the exact ceiling at 20,999,999.9769 BTC, just under 21 million.
- Issuance now: The block subsidy has been 3.125 BTC since block 840,000, mined on April 20, 2024. At 144 blocks a day that is about 164,250 BTC a year, before transaction fees.
- Next cut: The subsidy halves every 210,000 blocks. The next halving, at block 1,050,000, drops it to 1.5625 BTC. On October 25, 2026 the chain was at block 972,985, about 77,000 blocks short. At 10 minutes per block that is roughly a year and a half.
- Mined so far: On-chain data for October 25, 2026 showed 20,103,065 BTC issued, about 95.7% of the cap.
Ethereum
- No cap: ethereum.org says: "Unlike Bitcoin's fixed 21 million cap, ETH has dynamic supply mechanics."
- Issuance: Since the Merge, execution-layer issuance is zero. Validators receive consensus-layer rewards, about 1,700 ETH a day with roughly 14 million ETH staked, according to ethereum.org. The daily amount rises as more ETH is staked.
- Burn: The base fee on every transaction has been burned since the London upgrade in August 2021. If the average gas price reaches about 16 gwei on a given day, the burn offsets that day's issuance and net supply growth is zero or negative.
The two supply models are measured in different ways. Bitcoin's issuance is a fixed number of coins per block, cut in half on a known schedule. Ethereum's issuance changes with the amount of ETH staked and how much the network is used, so its net rate is reported as a percentage that can turn negative. Bitcoin's schedule tells you its future supply in advance. Ethereum's future supply depends on usage.
Side-by-side summary
| Bitcoin | Ethereum | |
|---|---|---|
| Main role | Peer-to-peer currency | Smart contract and application platform |
| Consensus | Proof-of-work (mining) | Proof-of-stake since September 15, 2022 |
| Block interval | About 10 minutes on average | 12-second slots |
| Supply limit | Just under 21 million BTC | No fixed cap |
| New supply | 3.125 BTC per block since April 20, 2024 | Validator rewards minus burned base fees |
