Winch Size Calculator

Whether you're a firefighter or a lover of off-road trips, our winch size calculator will prove itself useful to you. If you don't know why, that's even better - perhaps you've had no reason to investigate this topic so far!

However, since it's better to be safe than sorry, read on to learn what a winch is, why we use it, and how to use a winch. We'll also walk you through the winch pulling force calculation so you'll be able to answer "What size winch do I need?".

Winches are devices meant to help us lift or haul objects. They consist of a rotating part with a rope or chain connected to the object and some kind of sturdy anchor, such as a tree.

Winches are basically pulleys, which means that they increase our mechanical advantage. What does this mean? Since mechanical advantage is the ratio of effort to the load (weight being lifted), increasing it allows us to input less force and still lift the same weight, or lift more weight with the same force.

Although winches are present in many places nowadays, such as on boats or in elevators, we're going to focus on vehicle winches. Their overall role can be described as vehicle recovery, but it may be worth looking into specific applications:

• Righting a rolled-over vehicle;
• Moving or towing a load;
• Pulling the vehicle out of mud, water, snow, etc.; and
• Glider winch launch, where the winch is usually mounted on a heavy vehicle. Unfortunately, our winch size calculator doesn't cover this one, but works for the other applications!

There are several types of winches. When choosing the right one, consider the main purpose you'll use it for. The most common options are:

• Electric winch - Probably your best choice if you want to add a winch to your vehicle without too much hassle. It's pretty straightforward to use, and the motor does most of the job for you. It also can be used when the vehicle's engine isn't working.
• Hydraulic winch - Much sturdier than an electric winch, so much so you could consider it heavy duty. It generates a lot of force without overheating and generally offers a long lifespan.
• Lever winch - Powered by a handle moved back and forth, so a single person can operate one. How does this winch work? Instead of spools, it uses self-gripping jaws to move the rope through.
• Snubbing winches - You might have seen one on small boats to control the sails. The line is wrapped around a spool and can be tightened or loosened by pulling the tail line. There are no engines or other mechanisms involved.
• Air winch - Most commonly found at construction sites, industrial parks, and other building development sites. It's usually used to suspend or lift materials, and it's also more durable and safer than its electric and hydraulic counterparts.
• Wakeboarding winch - Something here for water sports fans. It pulls the person forward as the rope is wound in and can reach up to 40 kilometers per hour. They're also sometimes used by skiers and snowboarders.

Obviously, there are other types of winches out there you might be interested in, especially if you're a sailor. If you're unsure, always consult a specialist for advice to avoid disappointments and reduce risks related to choosing the wrong winch for your needs.

With that being said, the winch size calculator should work for most types of winches as long as the size remains the same.

We now know what types of winches are out there and how they can help us. It's high time we answered the question, "How do you calculate the winch size?". Just keep in mind that, in this case, size isn't its length or width, but the force it can exert. However, since newtons aren't the most intuitive unit to most of us, it's typically expressed as the weight it can lift (or pull).

Now that that has been clarified, it's time to calculate how big of a winch you need. We will consider both scenarios available in the winch size calculator.

The first case is when you need to right a rolled-over vehicle. This calculation is fairly simple if you follow these steps:

1. Estimate the weight of the load.
2. Find the position of its center of gravity, which is the distance to the center of mass, usually measured behind the front axle. Our car center of mass calculator can assist you with that.
3. Measure the height of the vehicle. Make sure that the units are consistent.
4. Use the formula to find the winch line pull to right the load:

winch line pull = center of gravity position * weight / height.

The units will be the same as for weight, typically kilograms or pounds.

What if you want to move the load after righting it? Well, you'll need a bit more data and need to follow these steps:

1. Find the damage resistance to account for any damaged wheels. This can be done using the formula:

damage resistance = weight * damaged wheels / original wheels,

where:

• original wheels - Number of wheels the vehicle normally has; and
• damaged wheels - Number of wheels that don't work for some reason. Note that twin rear wheels count as one.

2. Calculate the rolling resistance. You can use our rolling resistance calculator or do it yourself by dividing the weight by the ground factor, which depends on the surface type. The values are as follows:

3. Find the gradient resistance to account for the slope, if there's any. The values are:

Sometimes, you may find our slope calculator helpful in making estimates. The gradient value is positive if the slope is uphill, and negative if it's downhill.

4. Finally, calculate the winch size by adding the damage, rolling, and gradient resistances.

That's it! Hopefully, now you know how to calculate the winch size if you ever find yourself needing one.