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

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
• Use-phase emissions for pumps and motors
• Scope 3 supplier evidence

Sources: GHG Protocol Technical Guidance for Calculating Scope 3 Emissions, Appendix C: Calculating emissions intensity metrics, GHG Protocol Technical Guidance for Calculating Scope 3 Emissions, Category 11: Use of sold products, CEA, CO2 Baseline Database for the Indian Power Sector, version 22.0

Last reviewed 2026-10-31.