There is a simple formula for calculating the volume for resin required. Simply multiply length (metres) x width (metres) x depth (millimetres).
In this case - 1.5 metres x 1.5 metres x 5mm = 11.25kg of resin. This method will work for epoxy and polyester calculations.
For river resin tables we would recommend our clear cast epoxy resin as this will be more durable and will have less shrinkage than the polyester version.