Hook Size Calculator

Recommended Hook Size starts from a lookup table keyed by Target Species (panfish, trout, bass, walleye, pike/musky, or catfish) and Bait Size (small, medium, large), then Bait Type shifts the result: choosing Fly bumps the number up by 2 sizes, capped at 16, because fly hooks run smaller and lighter than the equivalent live-bait hook, while choosing Artificial Lure shifts it down by 1 -- toward the larger end of the scale, since this calculator follows the standard tackle convention where a lower or negative number (the "/0" range: 1/0, 2/0, and so on) means a physically bigger hook, not a smaller one. Hook Style is assigned from a separate species/bait-type lookup rather than computed from a formula: Aberdeen or Octopus for panfish and trout depending on bait, Wide Gap or Treble for bass, Octopus or Treble for walleye, Treble for pike/musky, and Circle for catfish. Gap Width in millimeters is derived from Recommended Hook Size through three piecewise-linear segments -- a shallow 0.3 mm step per size in the small-hook range, a steeper 0.8 mm step in the mid-range, and a 2.5 mm step per number once the scale crosses into 1/0-and-larger -- so gap width widens faster for the biggest recommended hooks than for the smallest.

Hook Strength (rated 1-10) also derives from Recommended Hook Size, with larger hooks (lower or negative numbers) rating stronger, plus a flat +1 bonus whenever the assigned Hook Style is Circle, reflecting that circle hooks are built to hold under load at a given nominal size. All three inputs are chosen from a fixed set of standard angling categories rather than continuous quantities, so this calculator is a lookup-and- recommendation tool grounded in common tackle-shop guidance, not a formula meant to be swept continuously across a range.