# Quit Smoking Savings Calculator

> Computes what a smoking habit costs per day, week, month and year from cigarettes per day and the pack price, projects 5- and 10-year savings (optionally invested at an annual return), the money already spent, and the life time regained at about 11 minutes per cigarette (Shaw, Mitchell & Dorling, BMJ 2000).

- Calculator id: `quit-smoking-savings` · Category: Health (`health`) · Tool name: `calculate_quit_smoking_savings`
- Canonical page: https://tttkmbb.com/health/quit-smoking-savings · This document: https://tttkmbb.com/health/quit-smoking-savings.md · JSON definition: https://tttkmbb.com/health/quit-smoking-savings.json

## Purpose

Computes what a smoking habit costs per day, week, month and year from cigarettes per day and the pack price, projects 5- and 10-year savings (optionally invested at an annual return), the money already spent, and the life time regained at about 11 minutes per cigarette (Shaw, Mitchell & Dorling, BMJ 2000).

**Use when:** You want the money and cigarettes saved by quitting, the amount already spent over the years smoked, or the future value of investing the savings.

**Do not use when:** You need a smoking-exposure measure for medical screening (use pack-years) or cessation treatment advice; the 11-minute figure is a population average, not an individual prediction, and the result is informational only, not medical advice.

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `cigarettes_per_day` | number |  | required | Average cigarettes smoked per day. (> 0, max 200) |
| `price_per_pack` | number |  | required | Price of one pack in your currency. (> 0, max 1000) |
| `cigarettes_per_pack` | integer |  | optional, default 20 | Cigarettes in one pack (20 in most countries; 25-packs exist in Australia and Canada). (min 1, max 100) |
| `years_smoked` | number | years | optional | Optional: years smoked at this rate, to estimate the money already spent at today's price. (min 0, max 100) |
| `annual_return_percent` | number | % | optional | Optional: annual return if each year's savings were invested (contributed at the end of each year); reports the value after 10 years. (min 0, max 30) |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `daily_cost` | number |  | cigarettes_per_day × price per cigarette. |
| `weekly_cost` | number |  | daily_cost × 7. |
| `monthly_cost` | number |  | daily_cost × 365 / 12 (average month). |
| `yearly_cost` | number |  | daily_cost × 365. |
| `savings_5_years` | number |  | yearly_cost × 5, at today's price and without investment returns. |
| `savings_10_years` | number |  | yearly_cost × 10, at today's price and without investment returns. |
| `cigarettes_not_smoked_per_year` | number |  | cigarettes_per_day × 365. |
| `lifetime_spent` | number |  | yearly_cost × years_smoked at today's price (only when years_smoked is given). |
| `invested_value_10_years` | number |  | Future value of investing yearly_cost at the end of each year for 10 years at annual_return_percent (only when given). |
| `time_regained_days_per_year` | number | days | cigarettes_not_smoked_per_year × 11 minutes, in days (Shaw et al. 2000 average). |
| `time_regained_note` | string |  | Sentence with the 11-minutes-per-cigarette estimate and its source. |

## Formula

`price_per_cigarette = price_per_pack / cigarettes_per_pack; daily_cost = cigarettes_per_day × price_per_cigarette; weekly_cost = daily_cost × 7; monthly_cost = daily_cost × 365 / 12; yearly_cost = daily_cost × 365; savings_5_years = 5 × yearly_cost; savings_10_years = 10 × yearly_cost; lifetime_spent = yearly_cost × years_smoked; invested_value_10_years = yearly_cost × ((1 + r)^10 − 1) / r with r = annual_return_percent / 100 (10 × yearly_cost when r = 0); time_regained_days_per_year = cigarettes_per_day × 365 × 11 / 1440`

Costs use today's pack price; real savings grow with tobacco price increases and inflation, which are ignored. The 11 minutes per cigarette comes from Shaw, Mitchell and Dorling (BMJ 2000), who divided the average 6.5 years of life lost by male smokers by the average lifetime consumption; it is a statistical average, not an individual forecast. Informational only, not medical advice.

## Data Sources

- Shaw M, Mitchell R, Dorling D (2000) Time for a smoke? One cigarette reduces your life by 11 minutes, BMJ 320:53 — https://www.bmj.com/content/320/7226/53.1 (peer_reviewed, retrieved 2026-09-24)
- CDC – Benefits of Quitting Smoking — https://www.cdc.gov/tobacco/about/benefits-of-quitting.html (government, retrieved 2026-09-24)

Data freshness: `static`. Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output.

## API

- `GET https://tttkmbb.com/api/v1/calculate/quit-smoking-savings?cigarettes_per_day=…&price_per_pack=…`
- `POST https://tttkmbb.com/api/v1/calculate/quit-smoking-savings` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/quit-smoking-savings · OpenAPI operationId `calculate_quit_smoking_savings` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool:  `run_calculator` with `{"calculator_id": "quit-smoking-savings", "inputs": {…}}`

## Example

- 20 a day, 30 per pack of 20, 10 years, 5 % return: inputs `{"cigarettes_per_day":20,"price_per_pack":30,"cigarettes_per_pack":20,"years_smoked":10,"annual_return_percent":5}` → `{"daily_cost":30,"weekly_cost":210,"monthly_cost":912.5,"yearly_cost":10950,"savings_5_years":54750,"savings_10_years":109500,"cigarettes_not_smoked_per_year":7300,"lifetime_spent":109500,"invested_value_10_years":137727.92,"time_regained_days_per_year":55.8}`
- 10 a day, 12 per pack, 15 years, 7 % return: inputs `{"cigarettes_per_day":10,"price_per_pack":12,"years_smoked":15,"annual_return_percent":7}` → `{"daily_cost":6,"yearly_cost":2190,"cigarettes_not_smoked_per_year":3650,"lifetime_spent":32850,"invested_value_10_years":30258.02}`

```
GET https://tttkmbb.com/api/v1/calculate/quit-smoking-savings?cigarettes_per_day=20&price_per_pack=30&cigarettes_per_pack=20&years_smoked=10&annual_return_percent=5
```

## Limitations

You need a smoking-exposure measure for medical screening (use pack-years) or cessation treatment advice; the 11-minute figure is a population average, not an individual prediction, and the result is informational only, not medical advice. Costs use today's pack price; real savings grow with tobacco price increases and inflation, which are ignored. The 11 minutes per cigarette comes from Shaw, Mitchell and Dorling (BMJ 2000), who divided the average 6.5 years of life lost by male smokers by the average lifetime consumption; it is a statistical average, not an individual forecast. Informational only, not medical advice. All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**Where does '11 minutes per cigarette' come from?**

Shaw, Mitchell and Dorling (BMJ 2000;320:53) divided the 6.5 years of life lost on average by male smokers by an estimated lifetime consumption of about 311,000 cigarettes. It is a population average with wide individual variation.

**Why is the 10-year figure not adjusted for price rises?**

Tobacco prices and taxes rise unpredictably, so the calculator uses today's price; real savings are usually higher. Use inflation to adjust if you have an assumed rate.

**How is the invested value computed?**

Each year's savings are treated as one deposit at the end of the year, compounded annually for 10 years: yearly_cost × ((1 + r)^10 − 1) / r.

## Related

- [Pack-Years Calculator](https://tttkmbb.com/medical/pack-years.md) — Cumulative smoking exposure for lung-cancer screening eligibility.
- [Compound Interest Calculator](https://tttkmbb.com/finance/compound-interest.md) — Grow the savings with monthly deposits at any compounding frequency.
- [Savings Goal Calculator](https://tttkmbb.com/finance/savings-goal.md) — Redirect the monthly amount towards a savings target.