Felt-unit conversion factors
These reference objects put a scientific quantity in familiar terms. Divide the quantity by its conversion factor; always retain the scientific unit alongside the comparison. A size comparison does not make driving, eating or using water interchangeable.
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0 reviewed factors are available for download. Only reviewed factor records carry CC BY 4.0; sample and draft factors remain visible below for transparency.
a week of dinners
The land behind the evening meals a typical person in this country eats in a week, using the country's diet pattern record.
This comparison is computed from a diet pattern rather than a fixed sourced conversion factor. It is excluded from the factor download.
tennis courts
Farmland area expressed as tennis courts. It is a size comparison, not a claim about where the land is or what else it could grow.
Factor: 261 m² · sample
23.77 m by 10.97 m, the singles and doubles playing surface. Run-off space around the court is excluded.
football pitches
Farmland area expressed as football pitches, useful once the area passes a few thousand square metres.
Factor: 7140 m² · sample
105 m by 68 m, the standard size for international matches. The Laws permit 100–110 m by 64–75 m, so real pitches vary by roughly a fifth either way.
km of driving
The same emissions expressed as distance in an average petrol car. Driving and eating are not interchangeable; this is a size comparison only.
Factor: 0.17 kg CO₂e per km · sample
UK fleet average, well-to-wheel. A specific car, or a fuller one, will differ.
Statistic record · UK government greenhouse gas reporting: conversion factors
short-haul return flights
The same emissions expressed as economy return flights within Europe. Aviation figures are themselves uncertain.
Factor: 300 kg CO₂e per passenger · sample
Order-of-magnitude figure for a European return trip including radiative forcing. Route and load factor change it substantially.
Statistic record · UK government greenhouse gas reporting: conversion factors
eight-minute showers
Freshwater withdrawals expressed as showers. This compares volumes only; it does not account for local water scarcity or mean that irrigation water could be used at home.
Factor: 65 litres · sample
About 8 litres a minute. A power shower can use several times this.