Trolling Motor Thrust Calculator – Find the Right Motor Size

⚓ Trolling Motor Thrust Calculator

Find the right thrust rating for your boat — based on weight, conditions & motor type

Quick Presets
📝 Calculator Inputs
⚓ Trolling Motor Thrust Results
📊 Trolling Motor Quick Reference
Kayak / Canoe
30–40
lb thrust
Jon Boat (14–16 ft)
40–55
lb thrust
Bass Boat
70–80
lb thrust
Pontoon Boat
80–112
lb thrust
12V System
30–55
lb thrust range
24V System
60–80
lb thrust range
36V System
80–112
lb thrust range
Thrust Rule
2 lb
per 100 lb boat wt.
💡 Thrust Rule of Thumb: Use at least 2 lb of thrust for every 100 lb of total boat weight (boat + gear + passengers). For heavy current or wind, increase by 20–30%.
⚡ Voltage & Shaft Length: Choose 12V for boats under 1,500 lb, 24V for 1,500–3,000 lb, and 36V for over 3,000 lb. Shaft length should be 20" per foot of freeboard above waterline.
📋 Thrust by Total Boat Weight
Total Weight (lb) Total Weight (kg) Min Thrust (lb) Recommended Thrust Voltage
Up to 500Up to 22710 lb20–30 lb12V
500–1,000227–45420 lb30–40 lb12V
1,000–1,500454–68030 lb40–55 lb12V
1,500–2,000680–90740 lb55–70 lb24V
2,000–2,500907–1,13450 lb70–80 lb24V
2,500–3,0001,134–1,36160 lb80–90 lb24V
3,000–3,5001,361–1,58870 lb90–100 lb36V
3,500–4,5001,588–2,04180 lb100–112 lb36V
🐟 Species & Recommended Setup
Species Avg Boat Size Thrust Needed Voltage
Largemouth Bass16–20 ft55–80 lb24V
Walleye17–20 ft55–80 lb24V
Crappie / Panfish12–16 ft30–55 lb12V
Catfish17–22 ft70–100 lb36V
Striped Bass20–24 ft80–112 lb36V
Trout / Stream10–14 ft20–40 lb12V
🔧 Shaft Length Guide
Bow Height Shaft Length Boat Type
0–10" (0–25cm)36" (91cm)Canoe / Kayak
10–16" (25–41cm)42" (107cm)Jon Boat
16–22" (41–56cm)48" (122cm)Bass Boat
22–28" (56–71cm)52" (132cm)Walleye / Multi-S
28–34" (71–86cm)60" (152cm)Pontoon / Pontoon
34"+ (86cm+)72" (183cm)Large Pontoon
📦 Motor Type Comparison
Motor Type Best Use Thrust Range Voltage Notes
Bow-MountBass / Walleye fishing45–112 lb12–36VBest control & maneuverability
Transom-MountJon boats, kayaks30–55 lb12–24VEasy install, budget-friendly
Engine-MountLarger boats55–112 lb24–36VUses outboard bracket
Hand-ControlSmall boats, canoes30–55 lb12VSimple, no foot pedal
Foot-ControlTournament fishing55–112 lb24–36VHands-free boat control
GPS Spot-LockAll scenarios55–112 lb24–36VHolds position automatically
Saltwater-RatedSaltwater / Bay55–112 lb24–36VCorrosion-resistant build
Wireless RemoteSolo fishing45–80 lb12–24VNo cables, remote operated

The thrust of a trolling motor is measured in pounds, and it simply points to how strongly the engine can push. Think of thrust as the basic force by which the engine pushes water backwards and moves your boat. A stronger engine gives more spin to the propeller which results in more power against the water and can handle heavy ships.

Here the question that each asks: how much thrust do you really need? Here is a rough rule that works out, about 2 pounds of thrust for every 100 pounds of the fully loaded weight of the boat. It covers passengers, gear, drinks, ice, everything that is on the deck.

How Much Thrust Do You Need for Your Boat

Another way to think about that: 5 pounds of thrust for every 200 pounds of whole mass. If you have a 2000-pound boat, you want at least around 40 pounds of thrust. At the end of the day, more force helps to escape problems with less effort.

I never heard that someone complains about a too strong trolling motor.

Trolling motors come in models of 12V, 24V and 36V. The heavy models, those with more then 100 pounds of thrust, work for pontoons. With 12V you reach around 55 pounds. The most common trolling motors have 72 to 75 pounds, which matches almost one horsepower.

But mind: bigger thrust not always gives bigger speed. Almost all trolling motors run at a similar maximum speed, because it depends on the motor itself and the size of the propeller. So even the best models reach only under 5 miles per hour.

For a canoe or kayak, a 20-pound engine does the task. With thrust up to 30 pounds you already reach the limit. A 28-pound engine works great on a typical fishing pontoon.

On the other hand, I saw an 80-pound engine on a 21-foot boat, that moves at more than 5 mph on smooth water and handles waves very well. There is also a setup with a 120-pound engine on a 28-foot boat, that carries almost 9000 pounds when fully loaded.

Wind and currents change everything entirely. A small 5-pound engine works well on a calm morning, but becomes almost useless when the water gets rough. A 55-pound engine on a 16-foot boat runs smoothly without big effort, but against back wind or incoming tide?

The battery drains soon. Good boating rules force you to prepare for hard situations, not only for calms. Saltwater engines work in fresh water even better, they simply have a stronger body against corrosion.

Pairing your engine with lithium batteries canreally extend the time of use.

From 36 to 55 pounds the improvement is modest, but the drain on the battery becomes a problem. The body of the engine itself must be much more strong to last that extra thrust.

Trolling Motor Thrust Calculator – Find the Right Motor Size

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