---
title: "Carbon Equivalent Calculator (CEV, CET, Pcm)"
description: "Carbon equivalent of a steel from its composition ✅ IIW CEV, EN 1011-2 CET or Ito–Bessyo Pcm ⭐ values outside a formula's validity range are rejected."
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![Carbon Equivalent Calculator (CEV, CET, Pcm)](/images/uploads/36e5d7c0-7baf-480a-b7c0-9c9d09c4324d/carbon-equivalent-calculator-weld-cross-section-macro-1920x1080.jpg)

Welding

# Carbon Equivalent Calculator (CEV, CET, Pcm)

Three published formulas — IIW CEV, EN 1011-2 CET, Ito–Bessyo Pcm — each enforced within its own validity window. Enter the ladle analysis in % by mass. A real GET form: computes correctly with JavaScript off.

   Formula CEV (IIW) CET (EN 1011-2) Pcm (Ito–Bessyo)

 This formula uses C, Mn, Cr, Mo, V, Ni, Cu — other fields are ignored, never silently mixed in.   Composition (% by mass)C %

Si %

Mn %

Cr %

Mo %

V %

Ni %

Cu %

B %

  Calculate [Reset](/calculators/carbon-equivalent.md "Reset the calculator to its default values") Recalculates on submit — the same value renders with JavaScript off.

### Result

 Valid range

CEV**0.434 %**

CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15

IIW / EN 10025-1

**Download as PDF** Result sheet · A4 Run a calculation first — then the sheet is ready to download.

Calculated on SteelEquivalents.com — send us the figures for a quotation.

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## Carbon equivalent — frequently asked

  Which formula should I use?

CEV (IIW) is the classic for C–Mn structural steels; CET drives the EN 1011-2 method B preheat calculation; Pcm (Ito–Bessyo) suits modern low-carbon, low-alloy steels. Follow whichever your welding specification names.

  What happens to elements the chosen formula does not use?

They are ignored — and the page says so above the fields. Each formula was fitted with its own element set; quietly mixing in extra terms would produce a number no standard defines.

  Why does the calculator refuse compositions outside the window?

Because the formulas are empirical fits, only validated inside their published composition windows. Outside them the number still computes — but predicts nothing. The refusal names the exact violated bound instead.