Don Taylor calculates it:
We … estimated that the social cost of smoking in 2000 was around $40/pack of cigarettes, distributed as follows:
• $33 private cost: borne by the individual, primarily through a substantially shortened lifespan
• $5.50 quasi-external cost: borne by the smokers’ family through increased health costs, slightly lower wages and other factors
• $1.50 external cost: borne by society, and representing the net effect of things like taxes paid, Medicaid and Medicare payments, and Social Security received