Outdoors blog


How Many Horsepower is 55 lbs. of Thrust? 

55lbs of thrust is equal to about 2 outboard horsepower engine and can move a tiny boat about 4mhp. The horsepower depends on prop and batteries.

Many of the people who use boats, kayaks, and other several vessels often wonder about a motor with high power.


They also believe in a false fact the more pounds of thrust their motor will feature, the more will be the speed that it will provide you their vessel. It cannot be totally agreed. If you specifically talk about trolling motors or even outboards motors then they depend on horsepower and prop pitch.

To understand the real power or the speed of your small boat is by determining its thrust and then knowing the horsepower it contains. But still making a direct comparison between horsepower and thrust is not reliable unless you also know the speed of the vessel when it is absorbing that thrust.

 Although you cannot make any direct comparison translation, you can still make an estimation about the horsepower rating of any trolling motor simply by multiplying the amp draw times the voltage so that you can determine the wattage of the motor.

So, following the exact procedure the estimated horsepower in 55lbs of thrust results to be 1 – 2 HP. This is a reliable one to give you a speed of around 4 miles/hours. 


The power that is being absorbed by your vessels is what we say the resistance that is multiplied by the speed at what it is traveling. The actual power that an engine can produce is substantially much larger than we get since the rest of the power is lost in several forms of energy required for the working of the motor.

With this, we can conclude to the fact that a typical propeller in the motor can only convert 50-60% of the horsepower that reaches into usable thrust and even some of the prop can give the best output up to 70%+. 


The first thing that you consider after spectating that the motor has labeled 55 lb thrust on it is that it is the maximum thrust offered by the motor.

So, after getting this fact let assume your motor is working at 1m/s, and still at this point, it will be offering a full thrust of 55lbs and calculating through the given fact you can come up to the result that it equals to 1/ 3 hp.

Now let’s contradict this fact with the actual working efficiency of any propeller, especially providing a thrust of 55lb. If the propeller has an efficiency of 50% then it is actually producing .049kW or 2/ 3 hp. Or let’s say your motor is 80% efficient at its full power so it actually produces 0.62kW. 

Now let something reverse, like what actually stands for 1 hp for any type of vessel either be one with 55lb or something more. So, one hp exactly lies between 75- 100 pounds of thrust. But getting these numerical facts are not so simple and even not directly convertible. It requires several facts about your motor, the thrust, and the speed as well.

This is the only fact on which the horsepower relies and that is the exact process to determine the working power of the motor. Additionally, you do not have the control in enhancing the working or the horsepower of your motor, because it is the built-in mechanism derived as per the brands.


But still you can maintain its proficiency level by having the proper maintenance and also by using it frequently. Because that’s not true fact that frequent use can degrade it, instead frequent use will make it more efficient.

So, the major fact is that you cannot make a direct comparison between thrust and horsepower until and unless you also know the speed of your vessel when it is that amount of thrust while working.

It is totally based on the practical application based on which we have calculated the estimated horsepower resulted by a vessel with 55lb of thrust which is obviously 1/ 3 hp. And to always receive the same amount of power make sure you are engaged with the proper maintenance and the best choice.

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