Grade I: Slightest possible murmur i.e. very faint, not heard in all positions, no thrill, often overlooked Grade II: Slight murmur i.e. soft, heard in all positions, no thrill Grade III: Moderate murmur i.e. moderately loud, no thrill Grade IV: Loud murmur i.e. loud, palpable thrill Grade V: Very loud murmur i.e. very loud, with thrill, heard with stethoscope partly off the chest Grade VI: Rare form, extremely loud murmur i.e. very very loud, with thrill, heard with stethoscope completely off the chest