Methodology

mergefees.com measures the cumulative revenue Bitcoin miners have earned by merge-mining other blockchains — reusing their Bitcoin proof-of-work to simultaneously mine chains that accept it and pay for it.

The definition. Revenue to Bitcoin miners = the block rewards (subsidy + transaction fees, or the miner's share where consensus splits the reward) of blocks that carry valid merged-mining proof — blocks actually produced by a Bitcoin miner reusing Bitcoin work. Every block is classified individually from its own consensus data; merge-mined status is never inferred from height ranges or dates.

How the numbers are built

• Per-block records. Every chain is walked block-by-block from genesis to tip, from the chain's own consensus data (fully synced nodes, or official endpoints validated block-for-block against them). Third-party aggregators are never the source of truth.
• Exact arithmetic. Monetary values are computed through integer base-unit intermediates (satoshis and equivalents) — floating point never touches a monetary value.
• Verification. Before a chain counts, it must pass: unbroken height continuity from genesis, per-record validation, consensus timestamp-skew bounds, and — where the chain has an emission schedule — the summed subsidy must match that schedule (in practice it matches exactly, to the smallest unit, on every chain here). Reference blocks are additionally spot-checked against independent explorers, and merged-mining proofs are cross-checked against the Bitcoin chain itself.
• The headline. Each chain's figure is the sum of miner rewards over merge-mined blocks only. Non-merged blocks are recorded but excluded.

Per-chain rules, in brief

• Namecoin (NMC). The full coinbase reward of every block carrying a valid AuxPoW proof. Merge-mined since October 2011 — the oldest and largest case.
• Syscoin (SYS). The miner's coinbase share only: consensus routes roughly a quarter of the block reward plus half the fees to the PoW miner; masternode and governance outputs are excluded. Today's chain is a 2019 relaunch — merge-mining on the 2016–2019 legacy chain is not reachable from any running node and is not counted (a stated undercount).
• Elastos (ELA). The merge-miner's output only, since consensus splits each reward between the miner and Elastos' council/staking systems. Elastos also allows non-Bitcoin proofs that imitate merged mining; those are detected structurally and excluded.
• Rootstock (RBTC). Rootstock pays no subsidy — miner revenue is transaction fees, paid out on a delay by its reward contract. Payouts are attributed to the block that earned them; recipients that are not Bitcoin miners are excluded. Early federation-produced blocks are excluded (they earned almost nothing).
• Hathor (HTR). The block reward of merge-mined blocks (a distinct consensus block type). Hathor transactions carry no fees, so revenue is subsidy only.
• Fractal Bitcoin (FB). The full coinbase of merge-mined blocks only — Fractal's consensus interleaves them with other block types that do not pay Bitcoin miners, so each block's own proof decides. The genesis and premine allocations are excluded.
• Electric Cash (ELCASH). The full coinbase of blocks whose AuxPoW parent is provably Bitcoin work (the parent's coinbase height and difficulty must match Bitcoin's schedule — the chain's later AuxPoW blocks ride on Fractal Bitcoin jobs and are excluded). Bitcoin pools mined it heavily from January 2021 to November 2024 and sporadically since (last seen July 2026). Caveats: payouts were restricted to project-whitelisted addresses throughout, and the market was too thin to sell the emission into.
• Core DAO (CORE) — hash delegation, reported separately. Bitcoin miners tag a Core reward address in their coinbase; Core's on-chain light client verifies each Bitcoin header and pays the miner an equal share of its validator's hash-power reward. Records are keyed by Bitcoin block and reconcile to the wei against on-chain payout totals. Not AuxPoW — the miner's work never produces a Core block — so it never enters the merge-mining headline. Payouts frozen by governance since 2026-08-31.

The two USD views

• Today's prices: all-time native units × current market prices — what the accumulated coins would be worth now.
• Valued as mined: each UTC day's revenue × that day's closing price, from cross-validated daily price histories — what miners would have realized selling immediately. Rootstock's RBTC is valued at the Bitcoin price (1:1 peg, validated against RBTC market data).

Where no reliable market price ever existed, as-mined revenue is excluded rather than guessed: Namecoin before late April 2013 (no aggregator or venue data survives) and Hathor before its September 2020 listing. Those amounts are shown in native units only. Carrying a later price backward would have overstated those eras severalfold.

Limitations worth knowing

• The Syscoin legacy-chain era (2016–2019) is missing, as above. Its current price reflects a mid-2026 exchange-delisting collapse — the as-mined and today views diverge sharply there by genuine market history, not error.
• Figures near each chain's tip lag by a safety window of confirmations, so a just-mined block appears after it is safely final — for Rootstock this lag is structural (~a day) because rewards mature slowly.

Status

Questions or corrections: the totals are recomputable from public chain data by construction — if you believe a number is wrong, we want to know.

Chains merge-mined with Bitcoin that are NOT in the headline

A 2026 survey verified every chain ever merge-mined with Bitcoin (from source code, live nodes, and on-chain samples). Beyond the tracked chains, three deserve explanation:

• Bitcoin Vault (BTCV), Nov 2020 – May 2025. Genuinely merge-mined by major Bitcoin pools — roughly 10.4M BTCV, nominally ~$270M at the prices of the time. It is excluded because its consensus allowed coinbases to pay only 100 project-whitelisted addresses, which held the coins rather than the pools. Whether Bitcoin miners were ever compensated is unknown, so it fails this site's definition of revenue paid to miners. The number is published here so the omission is visible.
• Core DAO (hash delegation), 2023 – present. Bitcoin miners tag a Core reward address in their coinbase and are paid CORE for their Bitcoin blocks (~$8M all-time). Their proof-of-work never produces a Core block — validators do — so it is reported as its own "hash delegation" category, never mixed into merge-mining totals.
• Electric Cash (ELCASH), Jan 2021 – present (sporadic since Nov 2024). Merge-mined by Bitcoin pools (~13.7M ELCASH, ~$54M as mined at thin-market prices). Included; each block's parent is verified as Bitcoin work, which excludes its BCH- and Fractal-parent AuxPoW blocks.

Smaller or dead chains that also qualified — Jax.Network (2022–23), Crown (2015–19), Xaya, Emercoin, Terracoin, Unobtanium, Myriad's SHA-256d slice, Freicoin, Devcoin, and a dozen others — together amount to a few million dollars historically and near zero today; they are documented but not tracked. Chains marketed as "merge-mined" that never paid Bitcoin miners for reused work (Anduro, drivechains, Hemi, DigiByte, Verge and others) are excluded outright.