What would be the volume of this object?

Hi :) I bought my daughter a sandbox and I want to try and figure the volume of it without just guessing. The leaflet says it is 92cm by 84cm by 38cm and it says the 38cm is the height which is obvious since its a sandbox. So how many kilograms of sand should I buy? I would only want to half fill it so she could sit in in and play. So I would need the proper volume and so I could half that. I know generally volumes are provided in litres, that's fine, if you could tell me in litres that would be great. Thanks so much :o)