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Calcimator

Trolling Motor Thrust Calculator

Calculate the minimum and recommended trolling motor thrust for your boat based on length, weight, and fishing conditions.

Inputs

ft
lbs

Results

Recommended Thrust

31 lbs

≈ 7 bags of sugar

Minimum Thrust25 lbs
Battery Capacity Needed60 Ah
Runtime on 100Ah Battery13.4 hours
How to Use This Calculator
  1. Enter your boat's overall length in feet (e.g., 16 ft for a typical bass boat).
  2. Input the loaded boat weight in lbs — include passengers, gear, fuel, and the motor itself.
  3. Select the worst conditions you regularly fish in: calm lake, moderate wind, river current, or rough water.
  4. Read the Recommended Thrust in lbs — choose a trolling motor at or above this value.
  5. Check Battery Capacity Needed to size your deep-cycle battery for a full 8-hour day.
  6. Use Runtime on 100Ah Battery to estimate how long a standard battery will last at average throttle.

How the result changes with Boat Weight (Loaded)

Boat Weight (Loaded)Recommended Thrust
68018 lbs
1,88050 lbs
3,32088 lbs
4,520120 lbs

What each input means

Boat Length
Overall length of your boat in feet. Longer boats present more surface area to wind and current.
Boat Weight (Loaded)
Total weight of the boat including gear, fuel, passengers, and equipment.
Typical Conditions
The worst conditions you regularly fish in. River current and rough water demand significantly more thrust.

What each result means

Minimum Thrust
The bare minimum thrust to move your boat in the specified conditions.
Recommended Thrust
Recommended thrust with a 25% safety margin above minimum for comfortable operation.
Battery Capacity Needed
Amp-hours of battery capacity needed for an 8-hour fishing day at average (60%) throttle.
Runtime on 100Ah Battery
Estimated runtime on a standard 100Ah deep-cycle battery at average throttle.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    Boat Length = 16, Boat Weight (Loaded) = 1200, Typical Conditions = 0 = 3 input(s) provided
  2. Calculate Recommended Thrust
    Recommended Thrust
    31 = 31
  3. Calculate Minimum Thrust
    Minimum Thrust
    25 = 25
  4. Calculate Battery Capacity Needed
    Battery Capacity Needed
    60 = 60

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