The IMO Proposal Calculator compares how four Member State proposals for the IMO Net-Zero Framework, submitted as circular letters, would change compliance costs for a shipping company under four illustrative compliance strategies, from 2030 to 2040.

• NZF As-is (Australia, Canada, South Africa, UK — CL.5216): The IMO NZF as approved at MEPC 83 modified to start 2029.

• NZF Softer Start (Brazil — CL.5214): Eases near-term targets, but converges on the NZF path in 2040s.

• NZF Enhanced Pricing (Tuvalu — CL.5215): Creates a pure tax on emissions up to Tier 2 and removes trading.

• Market-defined GFS (Liberia — CL.5213): Ties GHG trajectory to commercially available fuels, with no Fund or GHG pricing.

• Strategy 1 — VLSFO + bio-diesel: fossil fuel oil, and blend bio-diesel or use Remedial Units to meet targets.

• Strategy 2 — LNG + bio-methane: switch to LNG, and blend bio-methane or pay the Remedial Units to meet targets.

• Strategy 3 — VLSFO + ZNZ: fossil fuel oil, and use zero- or near-zero energy (ZNZ) to meet targets.

• Strategy 4 — 100% ZNZ: fully ZNZ and sell surplus compliance credits.

The IMO Proposal Calculator is a comparison tool driven by your organization’s assumptions, not a price forecast. Default fuel prices are drawn from the IMO's Comprehensive Impact Assessment on the global fleet for transparency and comparability with the wider IMO analysis; you can replace them with your own. The tool will be updated as decisions are made on the IMO NZF and details become clearer. 

Note: Our Concept Paper refers to a previous version of the IMO NZF Calculator, but the concepts are also applicable to the new IMO Proposals.