Trolling Depth Calculator
Estimate crankbait running depth based on lure, line out, trolling speed, and line type.
Distance from rod tip to lure
Use GPS-based speed for accuracy
Line Type
Estimated Running Depth
10.5'
Estimated Depth9.2–11.8'
Depth RangeSpeed effect: Optimal trolling speed
Line effect: Monofilament at standard depth — baseline for all lure ratings
• At 50 ft of line, estimated running depth is 10.5 ft (±1.3 ft).
• Lure depth ratings are from manufacturers at specific conditions — actual depth varies by rod angle and boat/line drag.
Frequently Asked Questions
Let out more line — most crankbaits need 40–60 feet of line to reach rated depth. Lighter, thinner line runs deeper (use 8 lb vs 17 lb mono). Switch from mono to braid with a fluorocarbon leader — braid has much less water resistance and can run 15–20% deeper. Slow your trolling speed slightly.
The Rapala DT-10 is rated to 10 feet depth at standard conditions (2.5 mph, 12 lb mono, 50 ft of line). With braid and longer line out (70-80 ft), it can reach 11–13 feet. The DT stands for "Dive To" — it reaches its rated depth at around 50 feet of line with 10–14 lb mono.
Walleye trolling speed depends on conditions and lure choice. Standard crankbaits like Rapala DTs and Reef Runners work well at 2.0–2.8 mph. On inactive days, slow down to 1.8–2.2 mph. On aggressive days or when targeting suspended fish, speeds of 2.5–3.2 mph work. Use a GPS-based trolling speed for accuracy.
Yes, significantly. Thinner diameter line has less water resistance and allows lures to dive deeper. Going from 17 lb mono (0.015") to 8 lb mono (0.010") can increase depth by 1–2 feet. Braid (same test as mono but much thinner diameter) can increase depth 15–25% over monofilament at the same trolling speed.