CDL practice test
Practice the three CDL knowledge tests most drivers take. Every question is written from the AAMVA model CDL manual, and every mock test uses the federal 80% pass mark. Free, no account.
Practice questions written from the AAMVA model CDL manual; not affiliated with FMCSA, AAMVA or any state licensing agency.
Choose a test
General Knowledge
Every CDL applicant takes it.
- In our bank
- 100 questions
- Mock test
- 40 of 50 to pass
Air Brakes
For a vehicle with air brakes.
- In our bank
- 38 questions
- Mock test
- 20 of 25 to pass
Combination Vehicles
For combination vehicles, such as a tractor-trailer.
- In our bank
- 40 questions
- Mock test
- 16 of 20 to pass
Pass mark and test size
Federal rules require at least 80% correct on every CDL knowledge test. Each state sets the number of questions, so test sizes vary by state. Our mock tests use the common sizes below.
| Test | Common size | 80% to pass |
|---|---|---|
| General Knowledge | 50 questions | 40 correct |
| Air Brakes | 25 questions | 20 correct |
| Combination Vehicles | 20 questions | 16 correct |
Rule source: 49 CFR 383.135(b)(1) (80 percent to pass a CDL knowledge test). Check your state licensing agency for the size of your test.
How the tests work
Practice
10, 20 or all questions. After each answer you see the right answer, a short reason and the manual page.
Mock test
The common test size and the federal 80% pass mark. You get a score and a list of questions to review.
Sources
Every question cites the manual section and the printed page. Each test page links the manual.
The CDL manual
Commercial Driver's License Manual, Modernized Testing System
AAMVA writes this model manual with support from FMCSA. Most states use it as their CDL manual. Read the manual (PDF, Service Oklahoma) or the CDL manual page on the FMCSA site.
We read this edition on 2026-10-05. Data and sources.
Questions
Which CDL knowledge tests do I need?
Every applicant takes the general knowledge test. You also take the air brakes test if your vehicle has air brakes, and the combination vehicles test if you want to drive combination vehicles. Endorsements such as passenger, school bus, tank and hazardous materials have their own tests. The manual lists the tests in section 1.1.1.
What score do I need to pass a CDL knowledge test?
Federal rules require at least 80% correct on each CDL knowledge test (49 CFR 383.135(b)(1)). That is 40 of 50, 20 of 25, 16 of 20 on the common test sizes.
How many questions are on each test?
The common sizes are 50 for general knowledge, 25 for air brakes, 20 for combination vehicles. Each state sets its own test, so test sizes vary by state. Our mock tests use the common sizes.
Are these the real CDL test questions?
No. examprepare.help wrote every question from the AAMVA model Commercial Driver's License Manual (March 2025 edition). Practice questions written from the AAMVA model CDL manual; not affiliated with FMCSA, AAMVA or any state licensing agency.
Is it free?
Yes. There is no account and no email. The test runs in your browser.