Sizing advice

Hello! I’m new to the community. Looking to buy my first pair of grant stones for everyday use. I’m looking at Diesel Boot Black Waxed Commander, but I’m nervous to buy a pair and have it not fit right. I wear adidas stan smiths size 9.5 and they fit me perfect- so I’m thinking of getting a size 9 D for my grant stones. Anyone have any advice? Tia