6'7" I believe. I seen him back in May when he was touring with Paul Gilbert. I walked in the front door of the venue and he was to the left behind his merch table selling. My immediate thought was "I knew he was tall, but holy shit." He is bordering on being a giant. So I watch the show and during it he introduces the drummer as his son. I see the two of them together afterwards back at their merch table. His son is just as tall as Greg. I couldn't tell when he was behind the kit.