CDL Passing Score (80%)
You do not pass the CDL written exams with a blended score. Each test is pass/fail on its own. 90% on General Knowledge and 76% on Air Brakes is a fail on Air Brakes.
The short answer
80% on each knowledge test.
| Test | Typical questions | Need correct (80%) |
|---|---|---|
| General Knowledge | 50 | 40 |
| Air Brakes | 25 | 20 |
| Combination Vehicles | 20 | 16 |
| Hazmat (H) | 30 | 24 |
| Tanker (N) | 20 | 16 |
| Passenger (P) | 20 | 16 |
A few states use a slightly different bank size. The percentage is still 80%. Confirm the question count on your state's handbook before you walk in.
Restrictions vs full fail
- Fail General Knowledge — no CLP for that visit
- Fail Air Brakes — you can still be licensed with an air-brake restriction (no air-brake vehicles)
- Fail Combination Vehicles — you do not get Class A; Class B may still be available if you passed the rest
- Fail an endorsement — you get the CDL without that letter; add it later
That is why you drill weak categories, not one overall mock percentage. CertReady’s dashboard is built for that.
How to study to 80%
80% is the floor. Aim at 85–90% on General Knowledge and Air Brakes so a bad cluster does not drop you to 38/50.
- Quick sets of 10 until explanations feel obvious
- One category at a time until it is above 85%
- Timed 50-question mock
- Read the study-guide numbers
All CertReady items are original practice, not live DMV questions.
Related: Class A vs Class B · CDL permit
Quick answers
- Is the CDL passing score 70% or 80%?
- Knowledge tests are 80% in the federal standard used by states. Do not study to 70%. Skills tests are scored on the state's score sheet, not as a percentage of written items.
- If I fail one section, do I retake everything?
- Usually you retake only the test you failed. Credit for tests you passed is a state timing rule — do not assume it lasts forever if you wait months.
- Does a 50-question CertReady mock match the real test?
- It matches General Knowledge length and the 80% bar. The live exam may draw a different mix. Use category scores, not one lucky mock, to decide when to book.
More CDL guides
CDL Class A vs Class B vs Class C
Class is about what the truck is rated to weigh and what you may tow — not the job title on the application. Book the wrong class and you either sit extra tests you do not need, or you cannot legally pull the trailer on day one.
CDL Permit (CLP)
The CDL is not one exam. You pass the written tests, the state prints a Commercial Learner's Permit, you wait, you practice, then you take the skills test. Searching “CDL permit” is the beginning of that sequence — not a different license.
California CDL Practice Test
California issues the CDL through DMV, to federal standards. The knowledge tests are the national topics — classes, space, air brakes, combination vehicles — plus CA’s own handbook. This page is practice for that written appointment, not a driving school.
Texas CDL Practice Test
Texas CDLs are issued by the Department of Public Safety. The written tests are the federal knowledge bank — General Knowledge, Air Brakes, Combination, endorsements — administered in Texas. Practice here, then book DPS.
Florida CDL Practice Test
Florida CDLs go through DHSMV / tax collector offices that offer driver services. The knowledge tests are the national CDL topics. Use this bank for the written part, then book Florida for the real exam.
Georgia CDL Practice Test
Georgia’s Department of Driver Services issues CDLs. The written exams are the federal knowledge tests. Practice the topics here, then schedule DDS.