The formula
Period cost = (pack price ÷ cigarettes per pack) × daily average × days.
Hypothetical difference = current-rate period cost − scenario-rate period cost. A negative difference means higher projected spending. Results are rounded to two decimal places after calculation.
What this estimate means
The rate may come from your own observations or be an estimate. It assumes an unchanged price and daily rate for every entered day. It is not a purchase ledger or confirmed savings. Whole-pack purchases, other spending and future price changes are excluded.
A 30-day period is not every calendar month. No currency conversions, interest, health benefits or physiological estimates are calculated. A lower cigarette count is a mathematical scenario, not a statement that smoking is safe.