Enter an amount of bitcoin and pick what you want to know: the footprint of holding it, of mining that many new coins, or of moving it. Every answer shows the lower and the higher published estimate of the network. For what the figures mean and whether you have to report them, read the carbon footprint of crypto and how to report crypto holdings in a carbon footprint.
Work out the carbon behind an amount of bitcoin
Cambridge (lower)
1,97 t CO2e
6.8 MWh of electricity
Digiconomist (higher)
5,64 t CO2e
10.1 MWh of electricity
Network totals: Cambridge Centre for Alternative Finance, 138 TWh and 39.8 MtCO2e a year (Cambridge Digital Mining Industry Report, April 2025); Digiconomist, 204.44 TWh and 114.03 Mt CO2 a year (Bitcoin Energy Consumption Index, read 30 October 2026). Block subsidy, fees, transactions and coins in existence from the Bitcoin blockchain at block 973,789 (mempool.space, 30 October 2026). Fees were 0.63% of miners' income over the last year. Holding and moving use the hybrid allocation method from South Pole and the Crypto Carbon Ratings Institute (2022). An estimate, not an audited figure.
The figures per bitcoin
| Reading | Cambridge (lower) | Digiconomist (higher) |
|---|---|---|
| Holding 1 BTC for a year | 1.97 t CO2e · 6.8 MWh | 5.64 t CO2e · 10.1 MWh |
| Mining 1 new BTC | 242 t CO2e · 0.84 GWh | 694 t CO2e · 1.24 GWh |
| One transaction (average fee) | 1.2 kg CO2e · 4.2 kWh | 3.5 kg CO2e · 6.2 kWh |
| Whole network, a year | 39.8 MtCO2e · 138 TWh | 114.03 Mt CO2 · 204.44 TWh |
How it is worked out
- Holding: the network's yearly emissions × the share of miners' income that is newly created bitcoin (99.4% over the last year, the rest being fees) × your share of all bitcoin (20,105,594 BTC existed at block 973,789). This is the hybrid allocation method from South Pole and the Crypto Carbon Ratings Institute's 2022 framework. Your share of value equals your share of coins, so the price drops out.
- Mining: each block creates 3.125 new bitcoin and blocks come about every ten minutes, so 450 a day are created. One bitcoin is 1/450th of a day of the whole network's electricity and emissions. All of it is put on the new coins, so treat this as the upper figure for "what it took to make".
- Moving: the fee share of the network's yearly emissions (0.63%) spread over the 207,948,827 transactions in the last year. A transaction paying a bigger fee would take a bigger share. Some publishers divide the whole network's footprint by the number of transactions, which gives hundreds of kilograms each; that overstates it, because the network uses the same power however many transactions it carries.
Worked example: a company that held an average of 25 BTC through its financial year would put 49.2 to 140.9 tonnes CO2e in its Scope 3 for those holdings, depending on the estimate, and say which estimate and method it used.
Jak pomáhá Carbon Recycling
Carbon Recycling works out the rest of your footprint, Scope 1, 2 and 3, from your bills, mileage, travel and spending with the UK government factors, and shows the method behind every line. This calculator gives you the crypto figure and its method to report alongside it.
Zdroje dat a licence
- Cambridge Centre for Alternative Finance (University of Cambridge): network electricity and emissions from the Cambridge Digital Mining Industry Report, 28 April 2025. Its live index is licensed CC BY-NC-SA 4.0, so we quote the published headline only and copy none of its data.
- Digiconomist (Alex de Vries-Gao): annualised totals from the Bitcoin Energy Consumption Index, read 30 October 2026, quoted with credit.
- Block height, rewards, fees and transactions: the public Bitcoin blockchain, read through mempool.space on 30 October 2026.
- Allocation method: South Pole and the Crypto Carbon Ratings Institute, Accounting for Cryptocurrency Climate Impacts (April 2022).
Neither Cambridge nor Digiconomist endorses this calculator. The figures are estimates for reporting and research, not financial or tax advice.