ZERO44, provider of software for maritime emissions compliance, has released a free, interactive fuel cost calculator on its website. The tool shows ship operators how the economics of replacing fossil fuel with biofuel change once carbon regulations are taken into account, and how that picture shifts year by year.

Beyond the price per tonne

According to ZERO44, fuel prices are still frequently compared on a one-to-one basis: what does a tonne of biofuel cost against a tonne of fossil fuel? If the comparison stops there, biofuel often loses due to its price premium.

“Too often, the conversation about alternative fuels stops at the price per tonne,” says Friederike Hesse, Managing Director at ZERO44. “But that doesn’t tell the whole story. Once you factor in regulatory costs and the value of over-compliance, the premium can turn into a net benefit. We built this calculator to make those mechanics visible.”

Under the calculator’s default assumptions, replacing one tonne of VLSFO with biodiesel on voyages within the EU results in a net benefit of around €163 in 2026. The outcome depends on many inputs: fossil and biofuel prices, the geographical scope of the voyage, and the prices for EU Allowances, FuelEU pooling and Scope 3 insets. The calculator brings these elements together in one view, allowing operators to understand the full picture.

Regulatory costs are set to rise: EUA prices are expected to increase, FuelEU targets tighten every five years, and the IMO Net-Zero Framework could add a global carbon price from 2029 if adopted in December. The calculator shows users how these effects combine over the years.

A starting point, not a decision tool

The calculator is intended for illustrative purposes only and is not part of the ZERO44 product. The company stresses that real fuel decisions are far more complex. Friederike Hesse: “Fleets operate on a diverse fuel mix, and some vessels are better candidates for alternative fuels than others, depending on engine compatibility and their trading patterns. On top of that, prices for fuels, allowances and surplus change continuously.”

ZERO44’s compliance software handles this complexity. It offers similar but far more extensive analyses for a company’s own fleet, including forecasting and scenario planning across EU ETS, FuelEU Maritime, UK ETS, CII and carbon insetting.

The calculator can be found here: www.zero44.eu/fuelcost-calculator