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HSI Calculator (Heaviness of Smoking Index)

Health

Calculate the Heaviness of Smoking Index (HSI) from time to first cigarette and cigarettes per day. A quick, validated 2-question nicotine dependence screen.

Written by · Reviewed by the thecalcu.com team · Last updated July 23, 2026

HSI Total Score

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This calculator computes your HSI Total Score from the values you enter.

Inputs
How soon after waking do you smoke your first cigarette?How many cigarettes do you smoke per day?
Outputs
HSI Total Score

Medical disclaimer: This calculator is for general information and educational use only. It is not a diagnosis and not a substitute for professional medical advice. Always consult a qualified healthcare provider about your health and before acting on any result.

What is a HSI Score?

The HSI Calculator scores the 2-question Heaviness of Smoking Index, a fast screening proxy for nicotine dependence combining time to first cigarette and cigarettes smoked per day. It's a shorter alternative to the full Fagerstrom Test for Nicotine Dependence.

This is a screening tool, not a diagnosis.

Why Use an HSI Calculator?

HSI captures much of the signal from the longer Fagerstrom Test using just two quick questions, making it convenient for a fast self-check. This calculator scores it instantly and privately, entirely in your browser.

Who Should Use This Calculator?

  • Smokers wanting a very quick dependence self-check without the full 6-question Fagerstrom Test.
  • Students of public health learning about abbreviated screening tool design.
  • Healthcare educators demonstrating how HSI relates to the full Fagerstrom Test.
  • Anyone curious about their nicotine dependence level.

What Insights Does the HSI Calculator Give You?

The HSI Total Score (0-6) is the sole output, reflecting your combined answers on time to first cigarette and cigarettes per day. Higher totals generally indicate stronger physical dependence; this calculator does not provide a clinical interpretation.

How to use this HSI Score calculator

  1. Answer how soon after waking you smoke your first cigarette.
  2. Answer how many cigarettes per day you smoke.
  3. Read your HSI Total Score instantly.
Show formula & methodology ↓Hide formula & methodology ↑

Formula & Methodology

Both questions are scored 0-3.

Total Score = Time to First Cigarette Score + Cigarettes per Day Score (range: 0-6)

Worked example, smoking within 5 minutes of waking (3) and smoking 25 cigarettes per day (2):

Total Score = 3 + 2 = 5

Frequently Asked Questions

What is the Heaviness of Smoking Index (HSI)?

HSI is a brief 2-question screening tool combining time to first cigarette after waking and cigarettes smoked per day into a single score, used as a quick proxy for nicotine dependence when a longer questionnaire isn't practical.

Is HSI a diagnosis?

No, HSI is a screening tool only, not a diagnostic instrument. It's designed to give a general sense of nicotine dependence level using just two quick questions.

How is the HSI score calculated?

Both questions are scored 0-3, and the two scores are added together for a total ranging from 0 to 6.

How is HSI different from the full Fagerstrom Test?

HSI uses only two of the six questions from the [Fagerstrom Test for Nicotine Dependence](/fagerstrom-test-calculator/), time to first cigarette and cigarettes per day, which research has shown to be strongly correlated with the full test's overall result, making HSI a faster proxy.

Why does time to first cigarette matter so much?

Smoking soon after waking is widely considered one of the strongest indicators of physical nicotine dependence, which is why it's one of just two questions retained in this abbreviated index.

What does a higher HSI score mean?

Higher totals generally reflect a stronger physical dependence on nicotine; this calculator does not provide a clinical interpretation, any specific concerns are best discussed with a healthcare professional.

Is my HSI answer data stored anywhere?

No, this calculator runs entirely in your browser and does not transmit, store, or share your answers anywhere.

Why use HSI instead of the full Fagerstrom Test?

HSI's two-question format is faster to complete than the full six-question Fagerstrom Test, making it convenient for quick self-checks or situations where time is limited, while still capturing much of the same dependence signal.

Can HSI help with quitting motivation?

Understanding your dependence level can help inform conversations with a healthcare provider about appropriate cessation support options, though HSI itself doesn't provide a treatment plan.

How does this relate to the Pack Year Calculator?

The [Pack Year Calculator](/pack-year-calculator/) measures cumulative smoking exposure over time, while HSI measures current physical dependence intensity, the two provide different, complementary perspectives on a smoking habit.
Also known as
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