# How do I calculate employee commuting emissions for a factory with 200 workers?

Canonical: https://senseible.earth/answers/employee-commuting-emissions-survey

Run a short survey asking each worker's usual mode and one-way distance, scale the answers up to all 200 workers, then multiply kilometres per mode by working days and a per-km factor. This is the distance-based method for Scope 3 Category 7. Label the result as a survey-based estimate.

## What to ask in the survey

Keep it to one screen or one paper slip. Ask supervisors to collect slips by shift; response rates are higher than with email.

1. Main mode of travel: walk or cycle, two-wheeler, car, shared auto, public bus, company bus.
2. One-way distance from home to the factory, in km.
3. If by car or two-wheeler: travelling alone or with others.
4. Days a week at the factory, and shift.

## Turning answers into tonnes

Use published per-km factors where you can, such as the India GHG Program road transport factors. The example derives factors from fuel economy and IPCC fuel factors, with the assumptions stated.

1. Scale respondents up to the full headcount, mode by mode, if response is below 100%.
2. Kilometres per mode = workers x round-trip km x working days.
3. Emissions = km x factor per km for that mode (per passenger-km for buses).
4. Add the modes. Walking and cycling count as zero.

## What is not Category 7

- A company-owned or company-fuelled staff bus: Scope 1, from its fuel invoices.
- A hired bus or cab contract paid by the company: usually Category 7 or a purchased service; follow one rule consistently.
- Business trips: Category 6, not commuting.

## Worked example: 200 workers, 300 working days (estimate)

- Mode split scaled from survey: 110 two-wheeler (10 km one way), 20 car alone (15 km), 50 bus (12 km), 20 walk or cycle
- Assumed factors: two-wheeler 2.31 kg CO2/L petrol / 45 km/L = 0.0513 kg/km; car 2.31 / 15 km/L = 0.154 kg/km; bus 2.68 kg CO2/L diesel / 4 km/L / 40 passengers = 0.01675 kg per passenger-km
- Two-wheeler: 110 x 20 km x 300 = 660,000 km x 0.0513 = 33,880 kg
- Car: 20 x 30 km x 300 = 180,000 km x 0.154 = 27,720 kg
- Bus: 50 x 24 km x 300 = 360,000 passenger-km x 0.01675 = 6,030 kg
- Total: 33,880 + 27,720 + 6,030 = 67,630 kg CO2, about 67.6 tonnes a year

Fuel economy and bus occupancy are assumptions; replace them with published per-km factors or your own data. The two-wheeler figure uses the unrounded 0.05133 kg/km.

## What Senseible does here

Senseible does not run commuting surveys or calculate Category 7. If the company pays for a staff bus, it reads those fuel slips and counts them in Scope 1.

- [Staff bus: Scope 1 or Category 7](https://senseible.earth/answers/staff-bus-scope-1-or-category-7)
- [Night shift cabs: which scope](https://senseible.earth/answers/night-shift-cab-emissions-scope-1-or-scope-3)
- [Scope 3 for MSME supply chains](https://senseible.earth/climate-intelligence/scope-3-emissions-supply-chain-msme-calculator)

Sources: [GHG Protocol Technical Guidance for Calculating Scope 3 Emissions (2013), Category 7](https://ghgprotocol.org/standards), [2006 IPCC Guidelines, Volume 2 Energy (petrol and diesel factors)](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html)

Last reviewed 2026-10-15.