HSI Calculator — Heaviness of Smoking Index

The HSI scoring system combines two primary behavioral indicators of physical nicotine reliance: daily cigarette consumption and the time interval between waking up and smoking the first cigarette of the day. Each parameter is assigned a categorical score ranging from 0 to 3. The final HSI score is the sum of these two individual scores, yielding a total range from 0 (very low dependence) to 6 (very high dependence). The mathematical relation is expressed as HSI = Score(Cigarettes Per Day) + Score(Time to First Cigarette).

Consider an individual who smokes 25 cigarettes per day and usually lights their first cigarette within 5 minutes of waking up. First, we evaluate the daily cigarette consumption: smoking 21 to 30 cigarettes per day assigns a sub-score of 2. Next, we evaluate the time to the first cigarette: smoking within 5 minutes assigns a sub-score of 3. Adding these values together (2 + 3), the total HSI score is 5, indicating a high level of physical nicotine dependence that typically requires structured cessation support.

Answer the two questions as honestly as possible based on your typical weekly smoking habits rather than exceptional days. Keep in mind that the HSI measures physiological addiction and does not capture psychological triggers, making it most effective when paired with a comprehensive behavioral quit plan. Consult a qualified medical professional to interpret your results and explore nicotine replacement therapies or counseling tailored to your score.