Editorial Policy
Every guide on this site, and the calculator page, is built from published sources and checked against them before it goes live. This page sets out which sources are used, how each guide is checked, and what the dates on a page mean.
Sources, in order of trust
Government agencies and statutes come first, then peer-reviewed research, then encyclopedias for history only.
- Government agencies and statutes, such as the National Institute on Alcohol Abuse and Alcoholism (NIAAA), the Centers for Disease Control and Prevention (CDC) and the National Highway Traffic Safety Administration (NHTSA) in the US, GOV.UK, legislation.gov.uk and the NHS in the UK, and state transport agencies in Australia.
- Peer-reviewed research found through PubMed, cited as the paper itself.
- Encyclopedias, for history only.
Forums and other calculator sites are read only to learn what readers ask. They are never a source for a number and are never linked.
How each guide is checked
Each guide passes six checks in turn, from a shared fact sheet to a score of 100 out of 100.
- Shared fact sheet. Every fact a page uses is first written into one shared fact sheet with its source and the quoted wording, so all pages use the same figure.
- Research audit. Each fact is opened at its source and marked confirmed, wrong or not in the source, and every number worked from it is recomputed.
- Chief audit. The finished draft is read in full, and every number is traced back to the fact sheet, with a separate check that nothing reads as permission to drive.
- Playbook check. An independent check of the page against the site's writing and linking rules.
- Scorecard. A guide needs a score of 100 out of 100.
- Overlap check. Pages are compared section by section, so two pages do not cover the same ground.
A guide goes live only after all of these steps pass. The drink tables on four pages are also recomputed by the calculator's own code on every build, so a table cannot drift from the calculator.
How the calculator works
The calculator uses the Widmark formula: grams of alcohol divided by body weight times r, where r is 0.68 for the male setting and 0.55 for the female setting. It treats all alcohol as absorbed and takes off 0.015% per hour. Time to 0.00 is also shown as a range at 0.020% and 0.010% per hour.
Calculators often disagree because they run the same formula with different r values and elimination rates, and some count hours from the last drink or skip elimination. The calculator here reports an estimate built on average constants. A person’s true level may differ from it, and no estimate stands in for a test.
What the dates mean
Updated on is the date the page text last changed. Editing a page moves the date; rebuilding the site does not.
Limits checked on a legal limit table is the date the government source for those limits was last opened and compared with the table. That date moves only when the source is opened again.
No medical or legal review
Pages are not reviewed by a doctor or a lawyer. They are written for general information, and each figure links to or names its source, so you can check it yourself.
Corrections
To report an error, email admin@baccalculatr.com with the page and the figure. A confirmed error is fixed, and the page's Updated on date changes with the fix.
Independence
The site has no sponsors, no affiliate links and no paid placements. No page is written for a company, a product or a law firm.