---
title: "Impact energy & toughness"
category: "impact-testing"
description: "Normalize Charpy or Izod absorbed energy to impact toughness aK using ligament area beneath the notch."
relatedStandards: ["ISO 148-1","ASTM E23"]
url: "https://vectorbtc.com.tr/resources/calculators/impact-energy/"
---

Computes aK = E / (b·h) in kJ/m² from machine energy and specimen dimensions at the notch. Charpy notch geometry reminders follow ISO 148-1 / ASTM E23 conventions.