Fitness Tracker

Material Composition Assumptions

Standard fitness tracker assemblies carry an average total weight of 35 grams. The dominant mass component is the printed circuit board assembly weighing 10 grams, representing 28.6% of device weight. Plastic housing materials constitute 9 grams or 25.7% of total mass. Lithium-ion battery cells contribute 6 grams at 17.1% weight fraction. Combined display screens and sensor modules account for 5 grams representing 14.3% of device mass. Metal structural components including fasteners and connectors weigh 3 grams at 8.6% of total. Remaining components including elastomer straps and miscellaneous parts comprise 2 grams or 5.7% of overall device weight.

The printed circuit board contains the highest carbon intensity materials including semiconductor dies, passive components, and rare earth elements embedded within multilayer substrate materials.

Manufacturing Geography

Fitness tracker production concentrates primarily within East Asian manufacturing hubs. China dominates global production volumes accounting for 65% of manufacturing capacity. Taiwan contributes 20% of global output through specialized semiconductor foundries and electronics assembly facilities. South Korea provides additional manufacturing infrastructure for advanced sensor technologies and display components.

The carbon intensity baseline reflects Chinese electricity grid emissions at 620 gCO2 equivalent per kilowatt-hour based on 2023 national averages. This elevated grid intensity significantly drives embodied carbon calculations since semiconductor fabrication and printed circuit board manufacturing require substantial electrical energy inputs during production processes.

Regional Variation

Manufacturing Region	Grid Intensity	Estimated CCI Score	Adjustment vs Default
China	620 gCO2e/kWh	3.0	baseline
Taiwan	509 gCO2e/kWh	2.6	-13%
South Korea	436 gCO2e/kWh	2.4	-20%
EU	275 gCO2e/kWh	2.0	-33%
Nordic	82 gCO2e/kWh	1.5	-50%

Provenance Override Guidance

1. Submit verified manufacturing facility location data including specific semiconductor foundry locations and final assembly plant coordinates to establish actual grid carbon intensity factors.

2. Provide detailed printed circuit board specifications including layer count, substrate materials, component density, and semiconductor process node technologies to refine embedded carbon calculations.

3. Supply battery chemistry specifications including lithium-ion cell capacity, electrode materials, and manufacturing origin to improve energy storage component carbon accounting.

4. Document transportation logistics including shipping modes, distances from component suppliers to assembly facilities, and final distribution pathways to end markets.

5. Furnish material sourcing documentation covering rare earth mining locations, plastic resin types, and metal alloy compositions to enhance upstream supply chain carbon assessments.

Methodology Notes

• The CCI score represents cradle-to-gate embodied carbon including raw material extraction, component manufacturing, and device assembly processes
• Scope 1 emissions dominate the carbon footprint through energy-intensive semiconductor fabrication and printed circuit board manufacturing operations
• Scope 2 emissions reflect electricity consumption during manufacturing processes, heavily influenced by regional grid carbon intensity factors
• Scope 3 emissions capture upstream material extraction and transportation activities across global supply chains
• Functional unit defined as one complete fitness tracker device ready for consumer use
• End-of-life disposal and recycling processes are excluded from current carbon accounting boundaries
• Device usage phase electricity consumption excluded due to negligible impact compared to manufacturing emissions
• Data gaps exist for specialized sensor manufacturing processes and advanced packaging technologies