How do I estimate the emissions from the office paper we buy?
Convert reams to weight, then apply a paper factor. A ream of 500 A4 sheets at 80 gsm weighs about 2.5 kg. Multiply total kilograms by a factor for virgin or recycled paper from a published table. It is Scope 3 Category 1 and usually small.
The weight
One A4 sheet is 0.0624 square metres. At 80 gsm that is about 5 g, so 500 sheets weigh about 2.5 kg.
The factor
Use a paper factor per tonne from a published set such as the UK government conversion factors, and pick recycled where your invoice says so.
A year of paper
- 400 reams x 2.5 kg = 1,000 kg of paper
- 1 tonne x the paper factor from your chosen table
What Senseible does here
Senseible reads quantities, dates and units from your bills and invoices and shows the factor and source used on every line.
Sources: GHG Protocol Corporate Value Chain (Scope 3) Standard, UK Government GHG conversion factors for company reporting
Last reviewed 2026-10-22.