Each onion having light and dark red colour The sizes of red onion vary between 30mm to 70mm. Packed in 5 Kg/10 Kg/20 kg/25 Kg mesh bag as per customer requirements. ... 1 Kg of red onion consists of 12 to 13 onion of 45-50mm. i.e. 13.5 tons in 20 feet one door box container.