CO2Stats

The Kettle Question

Your digital day

Say how often you do each of these in a day and see what a year of it comes to, as a range, from the figures we have approved from the ledger. Everything is worked out in your browser: nothing you enter is sent anywhere.

How many a day (each: text prompt). Up to 1000.

How many a day (each: image generated). Up to 1000.

How many a day (each: Google search). Up to 1000.

How many a day (each: hour of streaming video). Up to 24.

How many a day (each: hour of video call with the camera on). Up to 24.

How many a day (each: page view). Up to 1000.

No approved figure yet, so not counted: an ai video; an email. They are not zero; the ledger has no figure that fits a calculator yet.

A year of it

Enter how often you do something to see a year of it.

  • A cup of tea: 24.7 Wh, the ideal energy to heat 250 mL of water from 15 to 100 °C, before any kettle's losses (our calculation).
  • A shower: 1.92 kWh to heat an average-length mixer shower's 60 litres (the Energy Saving Trust's figures, our arithmetic).
  • A car mile: 0.26699 kg CO2e, an average car of unknown fuel, tailpipe only (DESNZ 2026); used only for CO2e figures.
  • Each activity counts different things, so they are never added together.

The figures it uses

Only figures an editor has approved from the ledger, each taken unchanged from one claim. Each counts what its claim counts.

The everyday comparisons

Heating one cup's water (250 mL, 15 °C to 100 °C) takes 4.18 J per gram per °C × 250 g × 85 °C = 88,825 J, or 24.7 Wh: the ideal, before any kettle's own losses. Our calculation.

Heating one shower's water: 60 litres × 27.6 °C × 0.00116 kWh per litre per °C = 1.92 kWh, before any boiler's losses: our arithmetic on the Energy Saving Trust's figures.

  • A mile in an average car: 0.26699 kg CO2e per mile. Tailpipe (scope 1) emissions of an average car of unknown fuel type, for UK company reporting. The well-to-tank emissions of its fuel are a separate factor and are not included. Greenhouse gas reporting: conversion factors 2026 (full set for all users), Department for Energy Security and Net Zero, 2026-06-11: "Sheet "Passenger vehicles", table "Cars (by size)", row "Average car", unit "miles", fuel "Unknown", column "kg CO2e": 0.26699"
  • An average-length mixer shower's water: 60 litres per shower. A seven-and-a-half-minute shower with a standard mixer showerhead at about eight litres a minute. At Home with Water, Energy Saving Trust, 2013-07: "The average reported shower was seven and a half minutes. ... Taking an average length shower, with a standard mixer showerhead (approximately eight litres/min), still uses less water (60 litres) than a typical bath (80 litres)."
  • How much a shower's water is heated: 27.6 °C per shower, from 13.4 °C mains to 41.0 °C. The report's assumed rise from mains water to shower water. At Home with Water (Appendix A, water temperatures), Energy Saving Trust, 2013-07: "Water temperatures: Mains 13.4; Shower 41.0, temperature rise 27.6 (°C)"
  • Energy to heat a litre of water by one degree: 0.00116 kWh per litre per °C. The report's specific heat capacity of water. At Home with Water (Appendix A), Energy Saving Trust, 2013-07: "specific heat capacity (kWh / L / K): 0.00116"
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