Blood alcohol concentration — Colorado Permit Test
Blood alcohol concentration on the Colorado permit test — 8 rules, each with the reason behind it and a question on it while it is fresh.
The rules
A driver may be convicted of DUI per se if their blood alcohol concentration is greater than 0.08%.
Above that figure the state does not have to argue about how you were driving. The number by itself is the offense.
A driver may also be convicted of DUI per se if the driver’s BAC is greater than 0.08%
A license may be revoked on a blood alcohol concentration over .02 if the driver is under 21.
Under 21 it is illegal to be drinking at all, so the driving limit is set near zero. One drink is enough to cross it.
based on a BAC over .08 or over .02 if the driver is under 21, or over .04 for a CDL driver
A license may be revoked on a blood alcohol concentration over .04 for a driver holding a commercial license.
A loaded truck takes far longer to stop and does far more damage. The people who drive them are held to a tighter limit for that reason.
based on a BAC over .08 or over .02 if the driver is under 21, or over .04 for a CDL driver
On average a person blood alcohol concentration drops by 0.015% per hour.
Only time sobers anyone up. Coffee, a cold shower and fresh air change how awake you feel and not how much alcohol is in you.
On average, a person’s BAC will drop by 0.015% per hour
A standard drink is 12 ounces of beer, 5 ounces of wine or 1.5 ounces of distilled spirits, and all three contain the same amount of alcohol.
People count glasses, not alcohol, so a beer feels smaller than a shot. The three measures named here are the same drink in different shapes.
A standard drink is defined as 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of distilled spirits
Once alcohol is in the bloodstream, only the passage of time will make a person sober as the body eliminates it through normal bodily processes.
Nothing speeds the liver up. Everything people try at the end of a night changes how alert they feel rather than how impaired they are.
Once alcohol is in the bloodstream, only the passage of time will make person sober as the body eliminates it through normal bodily processes.
A person’s blood alcohol concentration depends on the amount of alcohol consumed, body weight, the period over which it was drunk, the time since the last drink and the person’s sex.
Two people drinking the same amount end up in different places. That is why counting your own drinks tells you nothing about anyone else.
A person’s BAC depends on several factors: ● The amount of alcohol consumed ● Body weight
It makes no difference whether a drink is beer, wine or liquor, because standard servings of each contain about the same amount of alcohol.
Switching from spirits to beer is not cutting down. The measures the bar pours are made to hold roughly the same alcohol.
It does not make a difference whether a drink is beer, wine or liquor
On the test
Above what blood alcohol concentration is a driver DUI per se in Colorado?
0.08%. Above that figure the state does not have to argue about how you were driving. The number by itself is the offense. Colorado Driver Handbook, p.3: “A driver may also be convicted of DUI per se if the driver’s BAC is greater than 0.08%”
How this works
Most practice tests hand you a bank of questions and leave the manual somewhere else. This one puts them together.
You read one law and the reason behind it, then answer a question on that law while it is still fresh. Get it right and you move on; get it wrong and you have found the gap while it is cheap to fix, not on the morning of the exam.
Learning one rule at a time, and proving it immediately, is what turns a manual you skimmed into something you actually know — and it makes studying feel like getting somewhere rather than like waiting to find out.
What it costs
- One payment, once — not a subscription. Nothing renews and there is nothing to cancel, for an exam you sit one time.
- Free to start: a 10-question test and the first section of cards. No sign-up and no account.
- Paying opens the rest of the cards, unlimited full-length practice tests, and retests built from exactly the questions you got wrong.
- Every level up to Prepared — 3 tests passed in a row.
- Do the work, fail the real exam, and we refund you.
Where these come from
Every rule here is checked against Colorado Driver Handbook, published by the Colorado Division of Motor Vehicles, and against the state code itself. Last checked 2026-09-16.
- src/assets/drivers-manuals/CO.pdf (Colorado Driver Handbook, DR 2337 (12/05/24), Colorado Division of Motor Vehicles, retrieved 2026-09-14 from dmv.colorado.gov/publications)
- src/assets/drivers-manuals/CO.pages.txt (plain pdftotext over that PDF; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/SOURCES.json (sha256, folio offset 3, folioMarker, the extraction flag and the four trap measurements, each with its measured basis)
- 1 CCR 204-30, Rule 8 (402)(B)(4), the Colorado Department of Revenue rule stating the 80% pass mark for the DR 2252WE Driver's License Written Examination, read 2026-09-16 at law.cornell.edu/regulations/colorado/1-CCR-204-30-8
- docs/plans/colorado-exam-shape.md (what was searched and came up empty, and the 30-question practice quiz that must not become the exam's count)
- docs/work/colorado-corpus/plan.md (why the 40-question count was chosen, and the two figures it refused)