Quit Smoking and Nicotine Math
Smoke-free milestone timeline.
Enter your quit date and see each American Cancer Society milestone dated on your calendar, marked as reached, in progress or still ahead. The milestones are general statements for people who quit and are not a prediction for you. Runs in your browser; nothing is sent or stored.
Not medical advice. This tool does arithmetic on the numbers you enter. Talk to a doctor, pharmacist or quit coach before you change how you quit. In the US you can call 1-800-QUIT-NOW (1-800-784-8669); in Canada call 1-866-366-3667 toll-free to talk to a quit coach.
Your quit date
Your timeline
Fill the form and press Calculate.
Worked example
Quit on 15 January 2026 and check on 8 October 2026: that is 266 days smoke-free. The first two milestones (heart rate; nicotine and carbon monoxide levels) are reached, and "1 to 12 months after quitting" is in progress, running 2026-02-15 to 2027-01-15. The next one, "1 to 2 years after quitting", starts on 2027-01-15.
How it works
Each row is a line from the American Cancer Society page, placed by calendar arithmetic: 1 month and 1 year are added to your quit date as calendar months, and the 24 hours milestone is quit date plus 1 day. A row is "in progress" while today falls inside a range such as 1 to 12 months, and "reached" once the range has ended or when the milestone is a single point in time. ACS describes changes people notice and risk changes; individual results vary, and the page is general information, not a forecast for you.
Sources and basis (opened 2026-10-08): Health Benefits of Quitting Smoking Over Time, American Cancer Society. Quitline numbers: Speak to a Quit Smoking Counselor, Smokefree.gov (1-800-QUIT-NOW) and Quitting smoking: Provincial and territorial services, Health Canada (Canada.ca) (1-866-366-3667), both opened 2026-10-08.
Not medical advice. This tool does arithmetic on the numbers you enter. Talk to a doctor, pharmacist or quit coach before you change how you quit. In the US you can call 1-800-QUIT-NOW (1-800-784-8669); in Canada call 1-866-366-3667 toll-free to talk to a quit coach.
FAQ
What happens in the first days after you quit smoking?
The American Cancer Society lists that a few minutes after quitting your heart rate drops, and that 24 hours to a few days after quitting nicotine levels in your blood drop to zero and the carbon monoxide level in your blood drops to normal.
When does your risk of heart attack drop?
The ACS page lists 1 to 2 years after quitting as when your risk of heart attack drops dramatically.
How long until the lung cancer risk halves?
The ACS page says that 10 years after quitting your risk of lung cancer is about half that of a person who is still smoking.
Are these dates exact?
No. They are general ranges from the ACS list placed on your calendar. Your own recovery and risk depend on how long and how much you smoked and on other health factors.
Is this medical advice?
No. It is general information. A doctor, pharmacist or quit coach can talk through your own situation.