Ladder Height Chart And Calculator: Know Before Buying Ladder

Last Updated on July 31, 2022 by William R. Vargas

You have been searching for the perfect ladder for years but haven’t got your hands on it yet. Well, what if we introduce you to the easiest ladder height chart and calculator to find that ideal one?

Of course, cracking the perfect ladder height ratio is not an easy task. It takes a lot of time and patience. Nevertheless, with our guidelines, you can surely get the closest match in the shortest time.

Now, that sure sounds like a plan! So, without any more delay, follow our ladder length calculator to learn about all the crucial details and find your perfect ladder.

Why do we Need to Calculate the Height of Ladders?

Ensuring the appropriate ladder size is a crucial aspect of your safety. You see, when you are using a ladder for a project, you tend to get exposed to several risk factors.

For example, if your ladder is not long enough for a job, you need to stand on the top rung. Incidents like this put you in a vulnerable situation where you might even get injured.

Similarly, a super-long ladder will be extremely difficult to balance for some jobs where you do not need that much elevation. That is why you need different sizes of ladders to meet up your requirements.

And so, calculating the height of a ladder will give you a fair chance to choose the one that fits perfectly with your needs. Not just that, it will also protect you from unwanted incidents and mishaps.

Height Chart for Different Ladders

To begin our discussion, we will be presenting two different charts for the step and extension ladder. Therefore, pay close attention to the figures and take necessary notes if needed. First, let’s go starting with the step ladder height chart.

step ladder height chart

Ladder HeightMaximum Reach
4 Feet8 Feet
6 Feet10 Feet
8 Feet12 Feet
10 Feet14 Feet
12 Feet16 Feet
14 Feet18 Feet
16 Feet20 Feet

Now, we will know about the extension ladder height chart bellows:

extension ladder size chart

Ladder HeightMaximum ReachHeight to Top
16 Feet15 FeetMax. 9 Feet
20 Feet19 Feet9 – 13 Feet
24 Feet23 Feet13 -17 Feet
28 Feet27 Feet17 – 21 Feet
32 Feet31 Feet21 – 25 Feet
36 Feet34 Feet25 – 28 Feet
40 Feet37 Feet28 – 31 Feet

Straight Ladder height chart bellows:

Chart for Straight Ladder

Ladder HeightMaximum Reach
6 Feet5 Feet
10 Feet9 Feet
12 Feet11 Feet
16 Feet15 Feet

The charts denote the maximum reach of a distinct ladder. Hence, when you are buying one, these stats and figures along with the ladder height guide will help you get a better idea.

Calculating the Required Height of a Ladder

As you have seen in the previous section, we highlighted a few key figures in ladder height charts. Now, it is time to learn how to calculate it according to how tall a ladder you will need.

For better understanding, we will describe each of the ladders in separate sections.

Step Ladder

Let’s start with the basic one. That’s right. We are talking about the step ladders. Now, one thing that you should keep in mind is that when we are talking about step ladders, we are referring to ladders that are shorter than 20 feet.

To begin the process, start by measuring the height of your working area. Here, remember that the step ladder should be long enough to carry out your job. Normally, platform (step) ladders are used to get more strong and more stable bases to work in super relaxing ways indeed.

After that, add up your body height and the height of the ladder. We are now calling this combined height your working height. So, in simple words, the rule is to choose ladder heights that cover up your working height. Undoubtedly, you will get a concrete idea of it, when you can make a comparison between your working heights with the ladder height ratio.

To explain it further, let us consider the following example. Suppose you have a height of 4 feet. So, if you need to reach 20 feet, your ladder requires a height of at least 16 feet. You can observe different scenarios like this from the previous charts. You can use a step ladder height calculator for a perfect estimation for your required job.

Extension Ladder

After dealing with the step ladders, let us now proceed towards the extension ladders. The major difference here with extension ladders is that they are much taller than the step ladders and can be used as multi-purpose ladders.

That means, when you are setting an extension ladder, you will need to secure it at an angle for maximum stability. Now, you will also need some extra height here as you are leaning it on an angle from the pitch. Thus, you will end up needing a much larger height.

Luckily, you can initiate with a ladder angle calculator. Let’s take an example to calculate for a simple scenario. Imagine that you need to reach 16 feet from the ground level. So, after adding 3 feet extra with that, you need a 19 feet ladder.

Now, things are not that simple all the time. To calculate the safety margin, you need to add a foot in the ladder for every 4 feet. Check out the following equation for a better understanding. Here, you can get help from the extension ladder size guide.

Required Height= Working Height + (Working Height/4) + 3

That means, if your working height is 20 feet, you need (20/4)=4 additional feet for stable angle and 3 additional feet for balance. So, in total, you will need a ladder of 27 feet in height. You can also check out the ladder size chart once again to clear up any confusion.

Even, you can measure your ladder height by using a ladder rung calculator without any single mistake. Let’s make it more clear, suppose your ladder has 21 rungs in it. Then you call it 21 feet long ladder easily.

loft ladder calculator

If you’re considering installing a loft ladder, one of the first things you need to do is measure the opening in your ceiling. Then, It will ensure that you purchase the right-sized ladder for the job.

Here’s a quick guide on how to measure for a loft ladder:

  1. Measure the height of the opening from the floor to the top of the opening. It is the overall height that your ladder will need to be.
  2. Measure the width of the opening at the narrowest point. This will be the width of the ladder’s base.
  3. Measure the depth of the opening from the front edge of the opening to the back wall. This will be the length of the ladder’s steps. With these measurements in hand, you’ll be able to purchase the perfect loft ladder for your space.

ladder calculator trigonometry

If you need to calculate the height of a ladder, you can use trigonometry. It will give you the height of the ladder based on the length of the ladder and the angle of the ladder. Best of all, it will work for all the different-sized ladders as well.

To use the formula, you will need to know the length of the ladder and the angle of the ladder. The length of the ladder is the horizontal distance from the base to the top of the ladder. The ladder angle is the angle between the ladder and the ground. Once you have these two pieces of information, you can plug them into the formula to calculate the ladder’s height.

The formula is: Height = Length * sin(Angle)

For example, if the length of the ladder is 10 feet and the angle of the ladder is 30 degrees, the height of the ladder would be:

Height = 10 * sin(30)

Height = 10 * 0.5

Height = 5 feet

Keep in mind that this formula only works for right triangles. If the ladder is not a right triangle, the formula will not work.

What is the most common reason for ladder accidents?

Ladders are a common sight in many workplaces, but they can also be dangerous. According to the U.S. Bureau of Labor Statistics, ladder accidents account for more than 300,000 injuries each year. Ladder accidents can be caused by a number of factors, such as:

  • Failing to use a ladder safety system
  • Improper ladder placement
  • Failing to use the correct ladder for the job
  • Defective ladders
  • Negligence
  • Careless use of ladders

Failing to use a ladder safety system is one of the most common causes of ladder accidents. This includes using a ladder that is the wrong height, using a ladder that is not properly secured, and using a ladder that is not the correct type for the job. Improper ladder placement can also be a hazard, as can using a ladder that is in poor condition. Negligence and careless use of ladders are also common causes of ladder accidents.

A Few Tips for Safety

There is no doubt that a ladder height calculator is an excellent way to determine the correct height of your ladder. Still, we recommend you follow these safety tips while choosing your ladder.

  • Keep the legs and rungs of your ladder clean
  • Do not try to overpass 4 feet from your ladder
  • Ensure appropriate grip before carrying any work
  • Choose a larger ladder rather than a smaller one
  • Keep an eye on the load capacity of your ladder

By maintaining these safety precautions, you can avoid unwanted risks. Besides, it will also enhance your performance and make your job super-easy.

Ladders Accidents – Use & Safety Tips:

Different Load Capacity Ratings of Ladders:

There are different load capacity ratings of ladders that are available on the market. The load capacity rating is the maximum amount of weight that the ladder can support safely. It is important to choose a ladder with a load capacity rating that is appropriate for the job that you will be using it for. Some of the different load capacity ratings of ladders that are available include:

Type IAA ladders375 pounds.
Type IA ladders300 pounds.
Type I ladders250 pounds.
Type II ladders225 pounds.
Type III ladders200 pounds.
Different Load Capacity Ratings of Ladders

All Types of Ladders and Their Uses

Today we will about several types of ladders, which are frequently used to fulfill our daily necessities as well. So let’s begin the journey. I hope you guys enjoy it a lot.

1. Step ladders

Well, good step ladders could be used for many purposes, especially if it is best suited for household-indoor purposes. Usually, these ladders are shorter than 20 feet and you can easily touch your rooftop by riding on them. The ladder’s standing height depends on its default style and arrangements. If you are an owner of a small flat and apartment then it could be more beneficial for you. You can do several things such as hanging up paintings on the room’s wall, painting the rooftop, etc.


  • More safe & stable
  • Long-lasting and durable
  • Easy to move anywhere
  • Easy self-controlled
  • Fulfill all household purposes


  • Causes danger while using it on slippery surfaces

2. Extension Ladders

You might be wondering to know that, extension ladders are mostly used ladders in any industrial and emergency sectors. You can make it longer as your need. It is more stable and self-supportive than other self-supportive ladders.

The warehouses need more height to cover, exactly their extension ladders are used frequently to meet their need. Because of being two parts such as base and fly anyone can extend its height and length as their need.

As we know the base section is placed on the ground and the other fly part is used to move the ladders up and down. Only one man can ride on it and even he/she can move on fly part easily as their demand and need, including fixing it by a build-in locking system.

In terms of modern extension ladders, you can use a rope, or pivoted feet system to fix the ladders from different angles. Even you will feel stable on its surface area for best feet support. Extension ladders are best suited for long heights and outdoor activities.


  • Easily reach long-height industrial ceilings or roofs
  • Non-slippery surfaces area
  • Easily carry to anywhere you want
  • Heavy-duty ladders


  • Comparatively heavyweight than other ladders

Telescoping Ladders

Another widely used ladders name is telescope ladders. By this name you can easily understand that it can be folded during its idle time. Comparative to other ladders these ladders have a large type of steps in them, and it’s quite handy to move anywhere inside the room. We can change the bulbs if we needed.

As we these types of ladders are improved versions of extension ladders. Most engineers prefer telescope ladders rather than other traditional ladders due to their high safety and some versatile features.


  • Higher safety
  • Larger steps
  • Easily storable to anywhere
  • Sleek design
  • Good looking

4. Multi-position Ladders

Now, by hearing the name you can easily understand the purpose of this ladder. Exactly, I am talking about multi-position ladders. You can call it a multifunction ladder too due to its versatile necessity in our daily life. It is broadly used in the construction sector. If you are getting tired of your existing ladders then I will suggest you just go for it.


  • Higher safety with full support
  • Let you feel the freedom to do anything at the top
  • Take your position to complete high-height jobs


  • The small size might not be available everywhere

5. Platform Ladders

A platform ladder is a ladder with a large, flat platform at its top, instead of the usual smaller top step found on most ladders. This type of ladder is often used by workers who need to spend extended periods of time at a height, such as painters or window washers.

Platform ladders are available in a variety of sizes, with the largest models measuring as much as 20 feet tall. Most platform ladders have guardrails to help prevent workers from falling, and some models also include a handrail.
Platform ladders are typically made from aluminum or fiberglass, although some models are made from wood. Aluminum ladders are lightweight and easy to move, while fiberglass ladders are more durable and can be used in more hazardous environments.

When choosing a platform ladder, it is important to select the appropriate size and material for the job at hand. In addition, workers should be properly trained in how to safely use and maintain the ladder.


  • Long-Lasting
  • Easy to use
  • Self-supported design

What is the 4 to 1 rule for ladders?

The 4 to 1 rule is a guideline for ladder angle ratio for the placement of ladders. The rule states that for every four feet of height, the ladder’s base should be one foot away from the wall or object it is leaning against. This rule is meant to ensure the ladder’s stability and prevent accidents.

The 4 to 1 rule for ladders is a simple guideline that can help keep you safe when using a ladder. This rule is important because it helps prevent the ladder from tipping over and injuring the person using it. In addition, following this rule helps keep the ladder stable while you are using it. If the ladder’s base is too close to the wall, it can become unstable and cause you to fall.

What is the standard distance between rungs on a ladder?

When it comes to ladders, there are a few things you need to consider to stay safe. One of those things is the spacing between the rungs. So, how much space should be between rungs on a ladder?

The answer is that it depends on the ladder you use. For example, the rungs should be spaced about 12 inches apart on a standard A-frame ladder. But on an extension ladder, the rungs should be spaced about no less than 6 inches and no more than 12 inches apart.

You should always check the manufacturer’s recommendations for the specific ladder. But in general, these are the guidelines you should follow.

What is the maximum height of a ladder?

The Occupational Safety and Health Administration (OSHA) has a few restrictions in place regarding the height of ladders. The maximum ladder height that is considered safe to use is 30 feet. Anything over that height is considered too dangerous and is not recommended.

There are a few reasons why the maximum height of a ladder is only 30 feet set by OSHA.

The first reason is that it is too dangerous to go any higher than the average ladder height

The higher you are, the greater the risk of falling and injuring yourself. Therefore, it is to maintain your balance at such heights.

The second reason why the standard maximum height of a ladder is set to only 30 feet is that it is the maximum height that most ladders can safely reach.

How high can you reach with a 10-foot ladder?

The current measurement of ladder height vs. reach remains quite a mystery to many. It depends on a few factors, such as the type of ladder and the angle at which it is placed. For example, when properly positioned, most 10-foot step ladders can reach a height of about 14 feet. This means that the ladder will extend about 4 feet above the ground, which should be sufficient for most purposes.

On the other hand, if we are talking about an extension ladder or a straight ladder that is 10 feet in length, it will only reach 9 feet when placed against a wall. Why is this?

It all depends on the angle at which the ladder is placed against the wall. Most ladders are placed at a 75-degree angle against the wall, considered the safest angle for ladders according to the safest ladder angle calculator. So at a 75-degree angle, a ladder’s tallest point will be 9 feet if it’s an extension or a straight ladder. 


How high does a 40-foot ladder reach?

An extension ladder that is 40 feet can reach up to 36 feet to 37 feet in height. Also, as per the 4 to 1 rule ladder calculator, the distance of base placement from the wall will be 10 feet. A rule set by the U.S. The Office of Compliance states that your extension ladders’ two sections must overlap by 1.5 feet up to 36 feet. If you don’t understand those rules, you won’t be able to understand the correct ladder length equation.

So, If it’s 40 feet long, it must overlap by 2 feet. So if a 40 feet ladder consists of 2 sections of 20 feet in length, the adjusted reach will be 36 feet after 2 feet of overlapping. This is a critical length of ladder formula for extension ladders that should always be remembered.


FAQ – Frequently Asked Questions

Question: Is the 4:1 ratio rule difficult to understand?

Answer: For the first time you would be surprised to hear the 4:1 ratio as a safe ladder angle calculator. It will initiate you to make a proper setup for the high-height ladder. By following the ladder angle calculator you can get a correct and safe angle for your ladders.

It is said that any ladder should need to place at a ground 75 to 75.5-degree angle. Let’s make it more clear for better understanding; if you work on the 20 feet up from ground level then you need to place the legs of the ladder 5 feet away from your working wall. It’s easy to follow, not very difficult.

Question: What is the most unavoidable ladder safety rule?

Answer: Well, it seems to be a very important question to ask ladder enthusiasts so far. When anyone starts to ride on a ladder then he/she needs to follow the three points of the contract to be away from any kind of physical injury or accident. The climber should need to use two hands and one leg or two legs and one hand whatever they are following the ascending/descending order to ride on a ladder. In this case, quality ladders would be helpful for you.

Question: What is the cause of maximum ladder accidents?

Answer: Very sad, there are several reasons for ladder accidents surrounding us. A ladder is a common piece of equipment found in many workplaces. It is often used to reach high places, which can lead to accidents if not used correctly. The most common type of ladder accident is when someone falls off the ladder.

There are several reasons why people fall off ladders. One of the most common reasons is that the ladder is not stable. This can be caused by the ladder being placed on an uneven surface, or by the weight of the person using the ladder. Another common reason for people falling off ladders is when they lose their balance. This can be caused by the ladder moving, or by the person using the ladder being careless.

Other factors that can contribute to ladder accidents include the type of ladder being used, the weather conditions, and the height of the ladder. It is important to choose the right ladder for the job and to make sure that it is properly secured before using it. It is also important to be aware of the weather conditions and to avoid using a ladder in windy or rainy conditions. And finally, it is important to use the correct safety equipment when working at height and to always stay within the limits of the ladder.

Final Words

There you have it. Easy and accurate ladder height chart and calculator to find your perfect ladder. Now, judging by appearance, a slight height difference might not seem like a big deal.

However, getting the right size is an absolute necessity if you want to maximize your efficiency and protection. So, make sure to follow our guidelines and enjoy a safe working experience with your ladder.

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