Planer Depth Calculator

Pick your planer, set your trolling speed and how much line you've got out, and get a working estimate of how deep your bait is running. Built to match the real-world numbers from our planer fishing guide.

How to read this number

This is a working estimate, not laboratory physics — real depth moves with sea state, current, line diameter, and how clean your planer is running. The model matches the rules every planer fisherman learns the hard way: more line gets you deeper, but with diminishing returns as drag flattens the curve, and speed lifts the planer — every knot over trolling speed costs you depth. If the fish are marking at 25 feet and this says you're at 18, let out line or slow down, and give the change a few minutes to settle in.

For rigging — leader lengths, sea witch combos, and how planers fit into a full spread — the planer guide and the spread layout article cover the whole program.