According to that table, #6 would be pretty close to 16mm2.
Why are there such considerable differences between stranded and solid conductors? Around here, we use the total cross section, e.g. stranded 1.5mm2 means a wire with a number of strands, the sum of strand cross sections equaling 1.5mm2. So 1.5mm2 ist 1.5mm2, regardless of whether it is stranded or solid. The effective current carrying capacity is the interesting thing, not the cross section of the wire itself (there IS a considerable difference in that regard, which is why I hate using stranded wire for fixed wiring where space is ntoriously tight).
