Data Center Carbon Emissions Calculator by U.S. State

Data Center Carbon, per Year

Start from a tracked facility (optional)

US facilities on our data center map that have a published capacity. Picking one fills in its megawatts and state.

Capacity (megawatts)

From the developer's announcement, the utility filing, or the permit.

Share of capacity in use (%)

100% = running at full stated capacity all year, the upper bound. Facilities don't publish their real average draw, so try a lower figure to see a range.

State power grid

Average carbon per megawatt-hour of electricity generated in the state, in pounds of CO2-equivalent (EPA eGRID, 2023 data).

— tonnes of CO2e a year Carbon from its electricity

— gasoline cars Roughly the yearly CO2 of

— megawatt-hours a year Electricity used

Grid rates: U.S. Environmental Protection Agency, eGRID2023 summary data (summary tables, revision 2), table 3, total output emission rates, CO2e in pounds per megawatt-hour. Car figure: EPA, "A typical passenger vehicle emits about 4.6 metric tons of CO2 per year." Facility capacities come from our data center map records and are estimates. For the electricity behind one person's chatbot use, see the AI energy calculator.

How Much Carbon a Data Center's Electricity Produces

A 100 megawatt (MW) data center running at full capacity uses about 876,000 megawatt-hours (MWh) of electricity a year. On the U.S. average grid, that electricity produces about 306,315 metric tonnes of carbon dioxide equivalent (CO2e), roughly the yearly CO2 of 66,590 gasoline cars. Data center carbon emissions swing widely by state: the same facility produces about 20,742 tonnes on Vermont's grid and about 782,336 tonnes on West Virginia's.

CO2e combines carbon dioxide (CO2), methane and nitrous oxide into one figure, as the grid data from the U.S. Environmental Protection Agency (EPA) does. At Ban the Bots, we multiplied the facility's yearly electricity by its state's average grid rate from the EPA's Emissions & Generation Resource Integrated Database (eGRID). This is a calculation and does not measure any facility. You can check each line of that math in the calculator above.

The calculator has four inputs. Fill them in this order:

Start from a tracked facility (optional). The dropdown lists U.S. facilities on the data center map that have a published capacity. Picking one fills in its megawatts and its state.
Capacity (megawatts). This number box defaults to 100. Enter the facility's stated capacity here.
Share of capacity in use (%). This number box defaults to 100. At 100%, the facility runs at its full stated capacity all year, which is the upper bound.
State power grid. The dropdown defaults to "U.S. average." It lists every state, the District of Columbia and Puerto Rico, and each entry shows its rate in pounds of CO2e per megawatt-hour.

The results appear in three boxes. "Carbon from its electricity" shows tonnes of CO2e a year. "Roughly the yearly CO2 of" shows a number of gasoline cars. "Electricity used" shows megawatt-hours a year.

Three buttons sit under the results. "Copy result" copies the sentence, the math, the sources and a link. "Copy share link" copies a link that reopens the same inputs. "Print" prints a one-page sheet with the result, the math and the sources. A facility on the data center map can also open the calculator with its megawatts and state already filled in. The calculator runs in your browser, and nothing is sent anywhere.

Why the State Grid Changes the Answer

For the same 100 MW facility at full use, the state grid changes the yearly carbon figure by about 38 times between Vermont and West Virginia. EPA's eGRID2023 summary tables, revision 2, list each state's emission rate in pounds per megawatt-hour in Table 3, "State Output Emission Rates (eGRID2023)." The calculator uses each state's CO2e rate from that table.

A state rate is an average for all electricity generated in that state in 2023. The rate describes the state's power plants as a group and does not describe the power supply of any one facility. Rates run from 52.2 pounds of CO2e per megawatt-hour in Vermont, the lowest, to 1,968.9 pounds in West Virginia, the highest of the states. Washington is at 266.6, New Hampshire at 276.2 and California at 394.8. The U.S. average is 770.9 pounds.

Texas and Virginia show how much a state can change the figure. At 100% of capacity, a 100 MW facility gives about 306,434 tonnes on Texas's grid. Virginia's rate of 539.6 pounds gives about 214,408 tonnes for the same facility, which is about 92,026 fewer tonnes a year.

The Ban the Bots data center map lists capacity for many facilities. Its capacity figures are estimates from public utility filings, state permit records and news reports. The map lists OpenAI's Stargate campus in Shackelford County, Texas, at 1,400 MW, under construction. At 100% on Texas's grid, the calculator gives about 4,290,075 tonnes of CO2e a year, or about 932,625 cars. The map also lists a planned campus in Georgia, "Project Bunkhouse," at 1,830 MW. At 100% on Georgia's grid, the calculator gives about 5,216,537 tonnes a year, or about 1,134,030 cars.

The Formula and the Worked Examples

The calculator runs four steps. You can repeat them by hand with the same inputs.

Megawatts × 8,760 hours × share in use = megawatt-hours (MWh) a year.
MWh a year × the state's rate in pounds of CO2e per MWh = pounds of CO2e.
Pounds × 0.45359237 ÷ 1,000 = metric tonnes of CO2e, since 1 pound is 0.45359237 kilograms and 1 metric tonne is 1,000 kilograms.
Tonnes ÷ 4.6 = gasoline cars, since EPA gives about 4.6 metric tons of CO2 per typical passenger vehicle per year.

These are the calculator's own outputs for the inputs shown:

100 MW at 100%, U.S. average: 876,000 MWh a year, about 306,315 tonnes of CO2e, about 66,590 cars.
100 MW at 100%, Texas (771.2 pounds per MWh): about 306,434 tonnes, about 66,616 cars.
100 MW at 50%, Texas: 438,000 MWh a year, about 153,217 tonnes, about 33,308 cars.
100 MW at 100%, Virginia (539.6 pounds per MWh): about 214,408 tonnes, about 46,611 cars.
100 MW at 100%, Vermont (52.2 pounds per MWh): about 20,742 tonnes, about 4,509 cars.
100 MW at 100%, West Virginia (1,968.9 pounds per MWh): about 782,336 tonnes, about 170,073 cars.

The Vermont example worked by hand: 100 × 8,760 × 1 = 876,000 MWh. 876,000 × 52.2 = 45,727,200 pounds. 45,727,200 × 0.45359237 ÷ 1,000 is about 20,742 tonnes. 20,742 ÷ 4.6 is about 4,509 cars.

What the Number Leaves Out

The result is an estimate built from an average. It is not a measurement of any facility. Data centers do not publish their real average power draw facility by facility. Stated capacity is a maximum, so 100% is an upper bound, and a facility may use less.

The calculator leaves out several things that can change the real figure:

Power contracts. The state average does not reflect a facility's own power contracts, such as a purchase agreement for wind or solar power. Those contracts can raise or lower the real figure.
On-site generators. The state average does not reflect on-site generators, such as gas turbines or backup diesel generators. They can raise or lower the real figure.
Building and hardware. The calculator does not count emissions from building the facility or from making its servers.
The car comparison. EPA's vehicle figure assumes about 22.2 miles per gallon and about 11,500 miles a year. The car figure counts CO2 only, while the facility figure counts CO2e, so the car comparison is rough.

Using the Number at a Public Meeting

Describe the figure as an estimate from the state's average grid rate, with 100% of stated capacity as the upper bound. Name the source as EPA's eGRID2023 summary tables, revision 2, Table 3. Say that the rate describes the state's power plants as a group and does not describe the facility's own supply.

Then ask the applicant in writing for the figures the calculator cannot provide:

Expected electricity use in MWh a year, at average use and at peak use.
Where the facility's power comes from.
Any on-site generators, such as gas turbines or backup diesel generators, and how often they would run.
Any power contracts, such as a purchase agreement for wind or solar power.

Put these questions in a letter you can bring to the hearing. The data center comment letter page is one place to start. Use the data center map to find the capacity of a tracked facility near you, then enter that capacity here to get figures for your comments. Run the same megawatts through the data center power calculator and the data center water calculator before you write your comments.

Data Center Carbon Emissions Depend on Size and Grid

A 100 MW facility at full use comes to more than 200,000 tonnes of CO2e a year on the grids of Virginia, Texas and West Virginia. Vermont's grid puts the same facility at about 20,742 tonnes. Size and grid both set the result, and the grid can move it by about 38 times for the same facility.

Because the figure is an upper-bound average, ask the applicant for metered electricity use and its power contracts. The answer changes if a facility publishes its actual use and power source. The answer also changes when EPA publishes a newer eGRID. Enter the facility's megawatts and its state in the calculator to get its data center carbon emissions figure, then send the applicant the questions above in writing.

Common Questions About Data Center Carbon Emissions

▸ Do data centers produce carbon emissions?

Yes. The calculator estimates a data center's carbon from the electricity it uses, multiplied by its state grid's average rate. It does not count emissions from building the facility or making its servers.

▸ How much CO2 does a 100 MW data center produce?

At 100% of capacity on the U.S. average grid, a 100 MW data center produces about 306,315 metric tonnes of CO2e a year. On Vermont's grid the figure is about 20,742 tonnes, and on West Virginia's about 782,336 tonnes. These figures are estimates built from average grid rates and do not measure any facility.

▸ Why does the state matter?

Each state's grid has its own average emission rate, from 52.2 pounds of CO2e per megawatt-hour in Vermont to 1,968.9 pounds in West Virginia. The same facility at the same size therefore produces about 38 times as much on West Virginia's grid as on Vermont's.

▸ Does a data center that buys renewable energy have lower emissions?

This calculator cannot show that. It uses the state average and does not count a facility's own power contracts, such as a purchase agreement for wind or solar power. Those contracts can raise or lower the real figure, so ask the applicant in writing for its contracts and metered electricity use.

▸ How does this compare to cars?

The calculator divides tonnes of CO2e by 4.6, the EPA figure for metric tons of CO2 a typical passenger vehicle emits in a year. For a 100 MW facility at 100% on the U.S. average grid, that is about 66,590 cars. The comparison is rough because the car figure counts CO2 only and the facility figure counts CO2e.

▸ Where do these numbers come from?

The state rates come from EPA's eGRID2023 summary tables, revision 2, released June 12, 2025, Table 3, State Output Emission Rates. The car figure comes from EPA's typical passenger vehicle page, which gives about 4.6 metric tons of CO2 per year. Facility capacities on the Ban the Bots data center map are estimates from public utility filings, state permit records and news reports.