1 lb. Spool.
Tinned copper wires are already coated with solder ready to accept patinas, or leave silver.

THE HIGHER THE NUMBER-THE THINNER THE WIRE

14 gauge, .064" (1.6mm), 1 lb. (454g), 80' (24.4m).
16 gauge, .051" (1.3mm), 1 lb. (454g), 128' (39.0m).
18 gauge, .040" (1.0mm), 1 lb. (454g), 203' (61.9m).
20 gauge, .032" (.8mm), 1 lb. (454g), 323' (98.5m).
24 gauge, .020" (.5mm), 1 lb. (454g), 793' (241m)