CO₂ calculator
What reuse actually saves
Most of the emissions of an IT device arise in manufacturing — not in use, and not in disposal. Keeping a device in service instead of buying a new one avoids exactly that share. Here you can work out what it means for your quantities.
Your devices
Enter how many devices stay in use — either ones we purchased from you, or ones we refurbished and passed on.
Result
- Equivalent car distance
- –
- Equivalent tree uptake
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- Electronic waste avoided
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- Manufacturing avoided
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- Deduction for logistics & refurbishment
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Approximate figures. The calculation and its limits are set out below.
Method
How the figure is worked out
For a number to hold up in a report, it has to be clear how it came about. So every step is written out here.
The calculation
# per device type avoided = quantity × manufacturing emissions of one new device × (1 − 10 % for logistics and refurbishment) # example: 250 smartphones 250 × 45 kg × 0.90 = 10,125 kg CO₂e
- The premise. A reused device replaces a new one. What is avoided is the manufacture of that new device.
- Conservative. We deduct 10 % for transport, testing, spare parts and refurbishment.
- Use is left out. Electricity during use is the same whether the device is new or used.
Where the factors come from
From manufacturers’ environmental reports — Apple publishes a Product Environmental Report per model, Dell and Lenovo publish Product Carbon Footprints. Those values vary widely, because they depend on storage size, screen and place of manufacture. We therefore use rounded averages at the lower end of each range.
| Device | Figure used | Range |
|---|---|---|
| Smartphones | 45 kg | 35–60 kg |
| Tablets | 70 kg | 55–95 kg |
| Laptops | 200 kg | 150–300 kg |
| Desktop PCs | 250 kg | 200–400 kg |
| Monitors (24–27") | 220 kg | 150–350 kg |
| Smartwatches | 30 kg | 25–40 kg |
Comparisons
What we compare against
120 g CO₂e per kilometre
An average for a mid-size car in real driving. The comparison makes tonnes tangible, but it is an illustration and nothing more.
20 kg CO₂ per tree per year
A rough figure for a central European broadleaf tree. Young trees take up far less, old ones more — which is why we talk about tree years, not trees.
Electronic waste by device weight
Calculated with typical device weights. The mass is only avoided while the device stays in use — every device is recycled eventually.
Questions
Common questions about the calculator
Why does manufacturing matter so much more than use?
Because a great deal of energy and raw material goes into a smartphone or laptop, while using it draws little electricity. For smartphones, manufacturers put the manufacturing share of lifecycle emissions at roughly four fifths.
Does the calculator include the emissions of refurbishment?
Yes, as a flat 10 % deduction for transport, testing, spare parts and refurbishment. That allowance is deliberately generous.
Can we use the figure in our sustainability report?
As an order of magnitude with the source named, yes. For an auditable account you need data per device and a method your auditor accepts. We supply the device data and describe our procedure — assessing it against your reporting standard stays with you.
What about devices that can no longer be reused?
This calculation does not apply to them. They are recycled, which makes environmental sense but saves only a small part of what reuse saves.
Figures for your own stock
For the devices we handle we can provide the breakdown per job — quantity, device type and the share that was reused rather than recycled.