Is it advisable to ring sling a toddler? My 13 kg 2.5 yr old always gives me a shoulder ache when I sling him. Wondering if he's too big already.

You can continue to use a ring sling on your toddler if you are able to take the weight. However, it seems like the one-shoulder carry is putting on stress on your shoulder. You can consider soft structured carrier so that the weight is distributed among two shoulders and the waistband. Your toddler can most likely fit most of the toddler size carriers. We would recommend getting an ergonomic carrier than a hipseat as the seat is positioned further from your body and hence pulling the weight from your back. The ergonomic carrier which provides knee-to-knee support will also help to distribute the weight of your toddler better. For 13kg, my personal preference would be to do a back carry.

i feel that it is too heavy to sling a toddler of that weight. You are putting pressure on your shoulder and neck. You might consider a hipseat that is not so straining on your shoulder and is comfortable for both. Otherwise, do consider a stroller where he can sleep more comfortably and you don't feel the strain.