Shielding gas oxidizing equivalent calculator
Calculate the oxygen equivalent (OE) from the gas mixture’s O₂ and CO₂ percentages.
Enter both gas percentages to calculate OE.
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Method, scope & reference AWS D1.1 / D1.1M:2025
2025 base edition with July 28, 2026 errata. AMD1 not included.
Formula
The calculator uses volume percentages as entered. For example, 2% O₂ and 18% CO₂ gives OE = 2 + (0.5 × 18) = 11.
Scope and limitations
OE is one gas-composition value. It does not determine whether a shielding gas is classified or permitted for a particular filler metal, procedure route, transfer mode, or project. Confirm the applicable AWS A5.32 gas requirements, filler-metal classification/designator and AWS D1.1 requirements separately. The WPS must state the shielding gas and its nominal composition.
Reference basis: Cavoren’s AWS D1.1/D1.1M:2025 rule extraction for the oxygen-equivalent formula and Clause 5.6.4 shielding-gas routes. Verify the governing edition and project requirements before use.
OE calculator questions
Does OE include argon?
No. The formula uses oxygen plus one half of the carbon dioxide percentage. Other gases, including argon, are not added to the OE value.
Does an OE value approve a gas for my WPS?
No. The applicable filler-metal classification and permitted gas route must be checked separately. This calculator reports only the formula result.