How bidis are counted

What is a bidi?

Bidis, also spelt beedis, are “small, hand-rolled unfiltered cigarettes containing tobacco flakes rolled in unprocessed tobacco, tendu, or temburi leaf and tied with thread”. That definition comes from “Concept of BIDI years” (Datta et al, Lung India, 2022), the paper the References page links to.

The original calculator listed them as “Beedis”. Version 2 calls them “Bidis”.

How does the calculator count bidis?

• One bidi counts as half a cigarette, so 2 bidis count as 1 cigarette.
• Bidis are entered as a number a day, with the number of years.
• The calculator halves the number, multiplies by years, adds any other types and divides by 20.

Where does half a cigarette come from?

The References page says: “Bidis have been added to the calculator in 2024 for the first time. One Bidi is equivalent to half a cigarette.” It gives “Concept of Bidi years” as the reference. The paper proposes 43 bidis a day for a year as equal to one cigarette pack year, which is about 0.47 of a cigarette per bidi; the calculator rounds this to ½.

Like the other figures, it is an approximation. The References page says of the calculator as a whole: “This is not an exact science and approximations have been made.”

How do I enter bidis?

1. In the calculator, on “What have you smoked?”, tick Bidis, and anything else you smoked regularly.
2. The bidi step asks: “How many bidis a day, and for how many years?”
3. Enter the number a day and the number of years. Use a decimal point for part years, for example 2.5.
4. If the number changed, choose Add another period and enter each amount with its own years.

For a history with several periods or gaps, see entering a smoking history that changed.

After the tobacco steps, an optional history step asks whether you still smoke, when you stopped and how many years you smoked in total. FAQ 2 recommends recording stopping dates and years smoked alongside pack years.

What do 20 bidis a day for 20 years come to?

• 20 bidis × ½ = 10 cigarettes a day.
• 10 × 20 years = 200.
• 200 ÷ 20 = 10 pack years.

Someone who smoked 12 bidis a day and 10 cigarettes a day over the same 10 years would have 8 pack years: 3 from bidis (12 × ½ × 10 ÷ 20) and 5 from cigarettes (10 × 10 ÷ 20). The calculator’s breakdown shows each type separately.

What happens after the result?

The result screen shows the total and a breakdown by type of tobacco. You can download or email a PDF, print the result, or save a link to it. Clinicians can also copy a line for the patient record.

What are the limits?

Every bidi counts as half a cigarette; the calculator does not ask about size or brand. Pack years are a record of past smoking, not a diagnosis. If you are worried about your health, speak to your GP practice or use NHS 111. See how the calculation works for every conversion figure.