Hello, thank you for sharing your height and weight. According to the size chart of our product (Orange Patterned Slit Detailed Long Dress MG2325), size **XL or 2XL** is generally recommended for 1.78 cm height and 98 kg. However, to ensure a perfect fit depending on the pattern and fabric structure of the product, I recommend you to consider the following: - **Size Chart Check:** You can check your chest, waist and hip circumference from the size chart on the product page and choose the closest size. - **Flexibility:** With its slit detail and patterned design, this dress offers a comfortable and flattering fit that moves with your body. However, if you want a looser fit, you can choose 2XL, for a more fitted look, you can choose XL. If you share your exact measurements (bust, waist, hips), I can give you a more accurate recommendation. Also, if you have any questions about the product, I'm happy to help. Best regards, Deniz Madmext Team