How much carbon and how much CBAM, in five fields.

Method

What the math actually does

1. Mass reduction = original weight × (1 − density_new / density_old). Stiffness-equivalent rule of thumb that bakes in fibre-volume fractions; conservative vs. published Boeing/Airbus + Vestas / Siemens Gamesa figures.
2. Use-phase fuel + CO₂: industry-specific multipliers per kg of weight reduction. Aerospace commercial uses ~380 L jet fuel/kg/yr (fleet-average over the 25-year life of the aircraft); automotive EV uses ~9 kWh/kg/yr at 15,000 km annual driving on a mixed regional grid; wind uses ~4 MWh added energy per 100 kg of blade weight reduction.
3. Embedded-carbon delta: production-phase emissions of the new component (per-kg embedded × new weight) versus the old. Recycled CFRP at 8 kg CO₂e/kg vs virgin CFRP at 22 kg CO₂e/kg drives the swing.
4. CBAM exposure: embedded emissions × annual import volume × CBAM price. We use €90/tCO₂e at 2027 — the EU phased-in price; rises to ~€110 by 2030. If your switch increases embedded carbon (e.g. aluminum → virgin CFRP), the calculator surfaces it as a caveat instead of dressing it up.

We'd rather give you a defensible number you can take to your CFO than a vendor-flattering one. If your team has measured per-unit CO₂ figures from a third-party LCA — drop those into the workings request below and we'll re-run with your data instead of the industry mean.