what age or measurements is baby if they are a large size in the SWADDLE UP LITE GREY

Hi Stacey, size chart below. Sorry I have also now added this to the product.

Size: (according to your babies weight)
New Born    2 – 3.2 Kg
Small       3 – 6 Kg
Medium   6 – 8.5 Kg 
Large       8.5 – 11 Kg