Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Accounting identity, not a causal forecast. Currency basis, year and energy-system boundaries must be consistent.
Example Calculation
- Population: 1000000 people
- GDP per person: 20000 currency/person/year
- Energy per GDP: 0.002 GJ/currency
- CO₂ per energy: 50 kg/GJ
The entered factors multiply to 40 million GJ and 2 million tonnes CO₂ per year.
Frequently asked questions
How do I use this calculator?
Enter population, gdp per person, energy per gdp, co₂ per energy. The result updates automatically. Use Reset to restore the example values.
What method does it use?
CO₂=population × GDP/person × energy/GDP × CO₂/energy.. Accounting identity, not a causal forecast. Currency basis, year and energy-system boundaries must be consistent.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.