The reading path
Six rules keep an estimate legible
Use the same order for every published record: quantity, period, boundary, context, uncertainty, then missing evidence.
Quantity × factor
Start with a measurable activity quantity and multiply it by the published factor for that unit.
Worked example: 1,000 km × 180 g CO₂e / km = 180.0 kg CO₂e/yr
Annual period
Calculator quantities describe one year. Keep the annual period visible when carrying a result into a worksheet.
Worked example: 1,000 km × 180 g CO₂e / km = 180.0 kg CO₂e/yr
Boundary
Read the scope boundary before interpreting the result; it identifies what upstream, operational, or downstream activity is included.
Worked example: 1,000 km × 180 g CO₂e / km = 180.0 kg CO₂e/yr
Region + vintage
This worked example uses CA-ON and a 2023 factor vintage. Geography and year stay attached to every record.
Worked example: 1,000 km × 180 g CO₂e / km = 180.0 kg CO₂e/yr
Uncertainty
Published bounds describe a factor range when available. They do not turn a screening estimate into a verified inventory.
Worked example: 1,000 km × 180 g CO₂e / km = 180.0 kg CO₂e/yr
Missing evidence
Not available evidence is excluded from totals rather than converted to zero. Incompatible units remain separate.
Worked example: 1,000 km × 180 g CO₂e / km = 180.0 kg CO₂e/yr
Comparison note
Benchmark basis
Current Canadian and provincial comparisons use territorial, production-based emissions excluding LULUCF. Consumption and equity measures are not mixed into the calculator selector.
Benchmarks provide compatible context; they are not emission factors and do not change the published arithmetic.