Environmental calculations mostly come down to accounting: tracking a quantity — energy, water, carbon, waste — as it moves through a system, and converting between the units different sources use to report it. A kilowatt-hour of electricity, a litre of fuel and a kilogram of a given material each carry a different emissions figure depending on how that energy or material was produced, which is why comparable environmental figures are usually expressed in a common unit, such as carbon dioxide equivalent, rather than compared directly in their original units.
Calculators in this section
That conversion step is where most of the actual difficulty sits, more than in any single formula. Emissions factors and conversion rates between units of energy, volume or mass all shift depending on the source, the country and the year, so the same underlying activity can produce noticeably different figures depending on which reference values were used to calculate it. A defensible environmental estimate states which factors and assumptions it used, not just the resulting number.
This section brings together the calculators for that kind of conversion and estimation work — distinct from the physics and chemistry sections nearby, which deal with the underlying physical and chemical quantities rather than with tracking resource use or environmental impact over time.