# How do I calculate emissions from trucks idling?

Canonical: https://senseible.earth/answers/truck-idling-emissions-per-hour

Multiply idling litres per hour by 2.68 kg CO2 per litre of diesel. Take the idle fuel rate from telematics or the engine data, not a guess, then multiply by idle hours from the tracker. Idling is already inside your fuel invoices, so report it as a sub-figure.

## Getting the idle rate

- Telematics or engine data that logs fuel while stationary.
- A test: run the engine at idle for an hour and measure the tank drop.
- Use an assumed rate only if labelled as one.

## Do not double count

Idle fuel is part of the litres you already buy. Use the idling figure to target savings, not to add to the total.

## Cutting it

Engine-off rules at loading bays, auto shut-off and cab heaters or coolers that do not need the engine all reduce idle hours.

## Worked example: 20-truck fleet (one month, illustrative inputs)

- Idling at an assumed 2 litres per hour: 2 x 2.68 = 5.36 kg CO2 per hour
- Fleet idling: 20 trucks x 2 hours a day x 25 days = 1,000 hours
- Monthly idling: 1,000 x 5.36 = 5,360 kg CO2

The 2 litres per hour idle rate is an assumed input; replace it with your telematics figure.

## What Senseible does here

Senseible reads fuel invoices and fuel card statements (diesel 2.68 and CNG 2.69 kg CO2, IPCC 2006 defaults) into a fingerprinted Scope 1 record. Hired transport goes to the Scope 3 evidence trail, and distance or tonne-km estimates are labelled as estimates.

- [Telematics or fuel invoices for fleets](https://senseible.earth/answers/telematics-or-fuel-invoices-for-fleet-emissions)
- [Indian truck diesel mileage by size](https://senseible.earth/answers/indian-truck-diesel-mileage-by-size)

Sources: [GHG Protocol Corporate Standard](https://ghgprotocol.org/corporate-standard), [IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults)](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [GLEC Framework for logistics emissions (Smart Freight Centre)](https://www.smartfreightcentre.org/en/our-programs/emissions-accounting/global-logistics-emissions-council/)

Last reviewed 2026-10-21.