How to work out a CBAM liability from nine free resources

By Ahmed Medhat · Published26 September 2026

A CBAM liability comes from four numbers: the emissions embedded in the good, the free allocation deducted from them, the price of a CBAM certificate, and the tonnage. The rules for all four are set in acts you can read for free. Below are nine resources in the order the calculation uses them, then the arithmetic worked on one good, with every input taken from an act or a Commission publication and the cross-sectoral correction factor taken as 1.

1. The embedded emissions: Implementing Regulation (EU) 2025/2547

Implementing Regulation (EU) 2025/2547 sets how an installation calculates the embedded emissions of its goods from monitored data: the emissions attributed to each production process, the activity level, and the embedded emissions of the relevant precursors it consumes.

Which emissions count depends on the good. For the goods listed in Annex II of Regulation (EU) 2023/956 (the iron and steel goods it lists, aluminium, hydrogen and electricity), only direct emissions count. Cement, fertilisers and agglomerated iron ore (CN 2601 12 00) are in Annex I but not in Annex II, so their indirect emissions count too (Article 7(1)).

Embedded emissions are determined on actual emissions or by reference to default values (Article 7(2)); actual emissions count only once they are verified (Article 8(1)).

2. The default values: Implementing Regulations (EU) 2025/2621 and 2026/1740

Implementing Regulation (EU) 2025/2621 published the default values. Implementing Regulation (EU) 2026/1740 replaced its Annexes I and IV, applying from 1 January 2026 (Articles 1 and 2). For goods other than electricity, the table to read is Annex I of 2026/1740.

Read the "total emissions" column for your CN code and country. Where the country is not listed, or its field shows a dash, the value comes from the table "Other countries and territories" (Annex I, opening paragraph).

The same paragraph sets the mark-up added when the number of certificates is calculated: for cement, iron and steel, aluminium and hydrogen, 10 % for 2026, 20 % for 2027 and 30 % from 2028 onwards; for fertilisers, 1 % from 2026 onwards. A verified actual value carries no mark-up.

3. The free allocation deducted: Implementing Regulation (EU) 2025/2620

Implementing Regulation (EU) 2025/2620 sets the benchmarks and how the free allocation is deducted. Where default values are used, the specific embedded free allocation (SEFA) of a good is the year's CBAM factor × the cross-sectoral correction factor × the default CBAM benchmark in Column B of its Annex (Annex, point 4, Equation 6). The benchmark follows the production route of the default value used (IR (EU) 2026/1740, Annex I).

The CBAM factor is set in Directive 2003/87/EC, Article 10a(1a): 97.5 % in 2026, 95 % in 2027 and 90 % in 2028, falling each year to 14 % in 2033, with no CBAM factor from 2034. The Commission determines the cross-sectoral correction factor for each year. Until it is published, our sector calculator takes it as 1, and says so on the page.

The cost per tonne is then the default value with the year's mark-up, less the SEFA, times the certificate price, and never less than zero. For goods imported in 2026 the price is the quarterly average of EU ETS auction clearing prices for the quarter of importation (IR (EU) 2025/2548, Article 1(1) and (6)). For Q1 2026 it is €75.36 per tonne of CO₂e, published by the Commission on 7 April 2026 (Article 4(1)).

4. Two Commission reference files

• CBAM Questions and Answers: the Commission's answers to the practical questions the acts leave to the reader, 63 pages, updated May 2026.
• CBAM benchmarks workbook: the definitive-period benchmark values in a spreadsheet, by CN code and route. It is quicker to search than the act; the values that apply are the ones in IR (EU) 2025/2620.

5. The same arithmetic on one good

A worked example on published figures, with the cross-sectoral correction factor taken as 1. Rebar, CN 7214 20 00, imported in Q1 2026 from a country for which Annex I gives no value for that code, so the "Other countries and territories" value applies:

• Default value, route (C): 3.996 tCO₂e/t (IR (EU) 2026/1740, Annex I).
• With the 2026 mark-up of 10 %: 4.3956 tCO₂e/t.
• Benchmark, Column B, route (C): 1.364 tCO₂e/t (IR (EU) 2025/2620, Annex, point 5).
• SEFA: 1.364 × 97.5 % × 1 (cross-sectoral correction factor taken as 1) = 1.3299 tCO₂e/t.
• Chargeable: 4.3956 − 1.3299 = 3.0657 tCO₂e/t.
• At €75.36, the price of CBAM certificates for goods imported in Q1 2026 (IR (EU) 2025/2548, Article 1(1) and (6); published by the Commission on 7 April 2026): €231.03 per tonne of rebar.

That is the published figures worked through, not a figure for any installation. A verified actual value replaces the 3.996 and carries no mark-up. The certificates the declarant surrenders are the embedded emissions adjusted for free allocation under Article 31 of Regulation (EU) 2023/956.

6. Three free calculators, no login

• Sector CBAM cost calculator: runs this arithmetic by sector, route and country, 2026 to 2034. The carbon price is an input you can change.
• Default-value cost calculator: compares the cost on the default value, mark-up included, with the cost on a figure you enter, year by year.
• De minimis checker: whether an importer's CBAM imports stay within the 50-tonne annual threshold (Article 2a and Annex VII, point 1 of Regulation (EU) 2023/956). The threshold does not apply to electricity or hydrogen.

Our cost calculators take the default values and their mark-up, the benchmarks and the CBAM factor from the acts above. Verification is what establishes your actual figure (Article 8(1)).