Heaviness of Smoking Index (HSI) Calculator determines the nicotine dependence of a person by categorizing the person into three groups: low, middle, and high addiction.

If you want to calculate how many packs of cigarettes you have smoked in your life, check out our Smoking Pack Year Calculator. Additionally, if you need to check if a person is an alcoholic, make use of our Audit-C Calculator. Also, if you want to check your insulin sensitivity, make sure to visit this QUICKI Calculator.

Nicotine Dependence

What is nicotine addiction? (Heaviness of Smoking Index HSI)

According to the statistics, around 24% of population deal with cigarette dependence (addiction) problems in the USA. Therefore, it is a very serious issue that has been widely spread around the world. Generally, it occurs after some time of smoking. When you start consuming more and more cigarettes, you make it a habit, and the nicotine dependence always pushes you to smoke more.

If you consider the chemical composition of a cigarette (tobacco), you will see that the central part of tobacco is nicotine. It is the chemical that provokes addiction for an individual. When you take a cigarette and smoke it, it evokes a temporary pleasure in your brain, but it does not last long. As a result, you get caught in an infinite loop of smoking that has no limits, and you can’t easily stop it.

Why is Nicotine So Addictive?

As it’s already known to you, nicotine is the base chemical of tobacco. Therefore, when you smoke a cigarette or chew tobacco, it releases dopamine in the brain, temporarily making people feel good. However, the critical part is when that feeling goes away, the brain starts to crave it more and more, resulting in forcing you to inhale more smoke than the last time.

Nicotine gives your body more energy and pumps you with adrenaline. But, importantly, you need to be careful with its consumption because it can easily get out of control and evoke unwanted results. In other words, you can easily get addicted to it willingly or unwillingly.

Signs of Nicotine Addiction

Okay, you are aware of the nicotine addiction issues and its damage to your body’s health. But, what are the indicators or symptoms that can tell you if you are nicotine-addicted or not? 

Here is the list of some most common signs of nicotine dependence that you can easily spot:

  • You try and try to stop consuming it, but regardless of the number of attempts, you fail.
  • You give it a try to avoid consuming tobacco for some time, but it makes your body go worse. For example, you start feeling grumpy, anxious, or people can easily make you angry.
  • The body starts getting worse, and you experience serious health problems due to nicotine consumption, but you can’t stop.
  • You start avoiding people, and you have no problems with giving up going out with your friends if they don’t allow you to smoke in their places.
  • Tobacco is always on your mind. You always think of taking a new cigarette.

Heaviness of Smoking Index (HSI) – Definition

Heaviness of Smoking Index (HSI) is a test index that we use to measure how heavily an individual smokes. Additionally, it can tell you how addicted you are to nicotine. By definition, the HSI is based and was derived from the Fagerström Test for Nicotine Dependence. It uses two questions and measures the HSI based on the result:

  1. How long is the period after waking up before you have your first cigarette?
  2. How many cigarettes do you typically smoke per day?

Heaviness of Smoking Index – Interpretation

How high can the heaviness of the smoking index (HSI) be, and how do you interpret it?

Depending on what options you select for the two given questions in the smoking test, the HSI will be different for everyone. The maximum value HSI can reach is 6, and it is considered the worst-case scenario (high addiction state).

However, there are three groups or categories of nicotine dependence during the HSI measurement:

  • Low addiction (0-2 points)
  • Medium addiction (3-4 points)
  • High addiction (5-6 points)

What Does Smoking Do to Your Body?

Whenever you hear or read about smoking and its health issues, people generally associate it with lungs diseases. However, this is not the only damage a cigarette can do to your body. Clearly, it damages all the parts of one’s body and affects every organ.

Smoking drastically affects your lungs and other body organs (Heaviness of Smoking Index HSI)

Smoking can lead to various critical diseases such as:

  • Cancer
  • Heart diseases (stroke)
  • Lung diseases, 
  • Diabetes and chronic obstructive pulmonary disease (COPD)
  • Tuberculosis
  • Certain eye diseases
  • Rheumatoid arthritis
  • It can harm one’s memory and ability to concentrate
  • Affects brain development

Firsthand or the direct smoke you inhale to your lungs is not the only problem with smoking. Secondhand smoke or people around the smoker are also the big threats to nicotine and health diseases. Therefore, secondhand smoke can cause:

  • Lung cancer and coronary heart diseases
  • Sudden infant death syndrome
  • Acute respiratory infections
  • Middle ear disease
  • Asthma and respiratory symptoms

HSI Calculator – How to Use?

Using our HSI calculator is a piece of cake. Thus, you only need to answer two provided questions to measure an individual’s HSI. Next, we will see how to utilize the easiness and power of our HSI calculator and explain the process of using it step by step.

Step-by-step process:

  1. Find the time that passes before an individual has the first cigarette after waking up. Choose from the possible options: (60 min, 31-60 min, 6-30 min or within 5 min).
  2. Determine how many cigarettes an individual smokes per day: 10 or fewer, 11-20, 21-30, 31, and more.
  3. The HSI calculator will calculate the smoking index and return its value. Additionally, it will report whether you belong to a category of low-addicted, middle-addicted, or high-addicted smokers.

HSI Calculator – Example

Let’s make up a scenario and calculate the HSI for an imaginary person in the example below:

Scenario: What’s the nicotine addiction of a person who smokes a cigarette within 5 minutes after waking up. This person smokes, on average, 11-20 cigarettes per day?


  • within 4 minutes (+ 3 points) 
  • consuming 11-20 (+1 point)
  • The heavy smoking index of the person is 4 – Results interpretation: moderate addiction


What is HSI?

Heaviness of Smoking Index (HSI) is a test index that measures how heavily an individual smokes.

How do you calculate the smoke index?

Generally, there are two questions we ask an individual to answer, and for each answer, we grade it by a certain number of points. Therefore, the more points an individual gets, the higher nicotine dependence is.

How many cigarettes a day is considered heavy?

The population who smoke 25 or more cigarettes a day are heavy smokers, and they are very likely to suffer from health issues and diseases.

Is 10 cigarettes a day a heavy smoker?

People who consume 10 cigarettes a day are light smokers, and they are not highly exposed to cancer, lung, and other diseases. However, that doesn’t mean they are safe from unwanted damage to your immune system.

How many cigarettes a day is an addiction?

If you smoke as little as 4-5 cigarettes a day, it can easily lead to nicotine addiction. However, consuming 5 of them will have less harmful effects than 10+. Nicotine addiction is not dependent on the damage magnitude or how severe it can afflict your body. Thus, there is no safe zone for smokers. You are not safe from becoming addicted to it.

Can smokers live a long life?

Generally, scientists claim that smokers live 10 years less than non-smokers. So there is almost no chance that you will live a long life if you smoke a lot. However, some studies show that there are some exceptions.

How quickly do lungs heal after smoking?

From the day you stop and get rid of cigarette, it would normally take two weeks to three months for your lungs to start improving and healing. But to drastically improve, it takes a few years.

What’s the least harmful thing to smoke?

Vape, filtered cigarette, or hookah may sound a better and safer option for a smoker. However, it’s important to be aware that there is no “harmless” alternative.