# How do I express use-phase emissions per use, like per wash or per km?

Canonical: https://senseible.earth/answers/use-phase-intensity-metric-per-functional-unit

Divide your Category 11 total by the number of uses all products sold that year will deliver over their life. The GHG Protocol's example: 500,000 kg CO2e for 2,000 washing machines at 1,500 washes each is 3,000,000 washes, so 0.1667 kg CO2e per wash.

## Why a per-use figure matters

Category 11 counts the whole expected lifetime of every product sold in the year. A fan that lasts longer therefore shows a bigger total, even if it uses less power per hour. The Scope 3 Standard says companies should also report product lifetimes and intensity metrics so durable products are not misread.

## Pick the unit your buyer compares on

Appendix C of the Technical Guidance gives these examples:

- Can of cola: kg CO2e per 330 ml can
- Washing machine: kg CO2e per wash
- Television: kg CO2e per hour of viewing
- Car: kg CO2e per km driven

## The calculation

1. Take the Category 11 total for products sold in the year.
2. Uses delivered = lifetime uses per product x number sold in the year.
3. Per-use figure = Category 11 total / uses delivered.

## Report it beside the total, never instead

- The Category 11 total stays the required figure; the per-use number adds context.
- Use the same lifetime and use assumptions in both, and publish them.
- Other metrics the standard mentions: annual emissions per product, energy efficiency per product, emissions per hour of use, per km or per functional unit.

## Worked example: 4,000 ceiling fans sold in India (assumptions labelled)

- Assumed use: 2,500 hours a year for 10 years = 25,000 hours per fan
- 60 W fan: 0.06 x 25,000 = 1,500 kWh per fan; 4,000 fans = 60,00,000 kWh
- Category 11: 60,00,000 x 0.675 = 40,50,000 kg CO2, about 4,050 t
- Hours delivered: 4,000 x 25,000 = 10,00,00,000 hours
- Per hour of running: 40,50,000 / 10,00,00,000 = 0.0405 kg, about 41 g CO2
- A 28 W model on the same assumptions: 0.028 x 0.675 = about 19 g CO2 per hour

Hours, life and wattage are example assumptions. 0.675 kg CO2 per kWh is the India grid factor for FY 2025-26 (CEA version 22.0); use the grid of the country where the product runs.

## What Senseible does here

Senseible reads your own bills and purchase invoices; it does not model how customers use the products you sell. Use-phase figures and their assumptions come from you, and can sit beside your Scope 1 and 2 evidence when a buyer asks.

- [Calculating Category 11](https://senseible.earth/answers/use-of-sold-products-category-11-calculation)
- [Use-phase emissions for pumps and motors](https://senseible.earth/answers/use-phase-emissions-for-pumps-and-motors)
- [Scope 3 supplier evidence](https://senseible.earth/scope-3-supplier-evidence)

Sources: [GHG Protocol Technical Guidance for Calculating Scope 3 Emissions, Appendix C: Calculating emissions intensity metrics](https://ghgprotocol.org/sites/default/files/2022-12/AppendixC.pdf), [GHG Protocol Technical Guidance for Calculating Scope 3 Emissions, Category 11: Use of sold products](https://ghgprotocol.org/sites/default/files/2022-12/Chapter11.pdf), [CEA, CO2 Baseline Database for the Indian Power Sector, version 22.0](https://cea.nic.in/cdm-co2-baseline-view?mappingId=234&lang=en)

Last reviewed 2026-10-31.