Choosing the Best Length

*Please note that this video makes reference to a few discontinued lengths. See below for updated information.

Choosing the best length seat belt extender is an important part of making sure that you’re buckled up safely. The number one principle of choosing the best length is that you should choose the shortest possible extender that is going to get you buckled in where you otherwise couldn't buckle. When in doubt, default to shorter.

We suggest the shortest possible extender because most seat belt extenders are a fixed length, and when an extension is buckled in your seat belt will retract, using the full length of the extender. The shorter the extender, the better your seat belt fits. You want the receptacle of the extender to fall at least six inches to the far side of the center of your body. The more of the original seat belt that goes across your waist and your chest, the better.

The way that lengths are stated at Seat Belt Extender Pros is very important to understand when considering which length is best for you. Our extenders are measured by the amount of additional length you get when the extender is buckled in.

That means that seat belt extensions are not measured “tip to tail” or from one end of the metal tongue to the other end of the receptacle. Instead, imagine that the metal tongue is buckled into a receptacle, thereby disappearing, and then the remaining visible distance of the metal tongue to the end of the receptacle is the length, because that’s the additional length you get when the seat belt extender is buckled.


With that in mind, consider the following guide based on length and scenario.


7” - This is our most popular extender length and is great for many people and situations.

10” If you want the regular style, but the 7" doesn't allow you to buckle up, then the 10" might be a good solution if it's available. This is only offered for limited Extender Types.


The Adjustable Extender can become any length between 9.5" and 26". It is well suited for anyone who needs more than 10", as well as situations in which it is unknown how much length will be needed.


3” - The 3” Rigid Extender may be a great choice in numerous situations. It is suitable when a receptacle is buried or low in the front or back seats and inaccessible to the Buckle Booster. People also often enjoy this length when the seat belt is so tight that the occupant can't turn or breath reasonably and wearing the seat belt in that fashion is impeding driving - or also when the occupant is wearing bulkier winter clothes.

5” - A 5" Rigid Extender works when the 3" just isn’t getting the job done.

7” - The 7" Rigid Extender may be a great choice for people who are smaller bodied but have mobility impairments that impede motion in the shoulders, neck, and back and therefore can't otherwise buckle up. The reason is that it raises the receptacle to a more accessible position, thereby reducing the amount of movement required to buckle up. It is also an excellent length for most law enforcement, like police officers and sheriffs, because it raises the receptacle high enough to reduce interference with equipment on their utility belts. This helps the seat belt retract horizontally towards the door rather than in an arc around the body of the officer, potentially catching on something from the utility belt. This is also a common length for many plus-sized people.


Law Enforcement - As law enforcement personnel, if your challenge is your utility belt, measure from the top of the receptacle to just below the upper height of your utility belt when you’re sitting in your seat. That distance is likely 7-8”.

Plus Sized People - Larger people tend to have the widest variety of options regarding the extender they may get. Sit in your car and pull the seat belt across your body. Spread out the fingers of your hand so that your pinky and thumb are as far away as possible. Put your hand between the two unconnected ends of the seat belt with your pinky and thumb at either end. Half this distance on your hand should encourage you to try a 3” or 5” Rigid Extender. If this distance is about that between the ends of your pinky and thumb or more, try the 7” extender. If you require much longer, consider the Adjustable Extender (which is not rigid).

People with Disabilities and/or Mobility Impairments - If the seat belt fits across your body and buckles in but you have mobility impairments due to a chronic medical condition, injuries, surgeries or other challenges that prevent you from buckling up without an extender, then choose the shortest possible length that will allow you to buckle up again. Typically, a 5” or 7” Rigid Extender is the best length due to the rotation of the arms, body, torso and back otherwise required to buckle up that you may not be able to do. If you want to be more precise, sit in the seat and try buckling up. Measure the distance between the two ends of the seat belt when the task of buckling up becomes impossible to complete. That is the length extender that you should consider.

Limo, Uber, Taxi, Ride-share, NEMT - Those who transport other people in their vehicles should consider the Adjustable Extender, as it allows the passenger to adjust the extender to the length that most suitably accommodates his needs.

Low or Buried Receptacle - If you have a low receptacle in the front seat, try the 3” or 5” Rigid Extender so you can access the receptacle and buckle up where you couldn't before. If you have a low or buried receptacle in the backseat, check out the Buckle Booster, which doesn't provide length but helps keep the seat belt receptacle accessible.

The Elderly - In most cases, the 3” or 5” Rigid Extender does the trick. If your buckling challenge is related to arthritis, joint pains or other general discomforts, try buckling up and at the point the pain makes buckling up no longer possible, stop and measure the distance between the two ends of the seat belt. Try that length extender.

Bulky Clothes or Coats - If your seat belt is already feeling like it's too tight, wearing bulky clothes like winter coats may make it impossible to buckle up. Give yourself some breathing room with a 3" extender.


Already know which extender style is best? Click HERE to shop by car.

Need more information before choosing? Click HERE to learn more about extender style.