Free California CDL practice test online
Take a free California CDL practice exam online with clear explanations—no sign-up. Coverage includes general knowledge, vehicle systems, combination vehicles, cargo, and endorsements. Then verify current requirements with California Department of Motor Vehicles.
CDL knowledge tests are federally regulated, so the passing score in California is the same as everywhere else: 80% correct on every knowledge test. You must also hold a commercial learner’s permit for 14 days before the skills test.
New to the knowledge test? CDL endorsements explained · One-week study plan
Requirements before you test
California CDL test requirements
Commercial licensing is largely federal. Any figure above credited to a 49 CFR section applies in every state — see 49 CFR 383.135(a)(1) and 49 CFR 383.25(e). A figure credited to California Department of Motor Vehicles is California’s own, and may be stricter than the federal floor. Test length, fees, and scheduling are set by California Department of Motor Vehicles (official source).
Entry-Level Driver Training comes first
Since February 7, 2022, a new Class A or Class B CDL, a class upgrade, or a first passenger, school bus, or hazardous materials endorsement requires training from a provider on the FMCSA Training Provider Registry (49 CFR 380.600). Practice questions are study material and do not satisfy that requirement.
FMCSA Training Provider RegistryYou need a California licence first
A commercial learner’s permit only counts if you already hold an ordinary licence from the same state (49 CFR 383.25(a)(2)). The California non-commercial knowledge test runs 46 questions and needs 38 correct, with permits issued from age 15 years, 6 months.
California permit practice testWhat you will practice
Build coverage topic by topic.
Each question carries a topic, difficulty, explanation, and source section so your review has context.
Sample questions
5 California CDL practice questions
Try these California sample questions now — each shows the correct answer with a plain-language explanation and a source section. The full 600-question bank is in the practice run.
1. Ammonium nitrate and hydrogen peroxide as oxidizers are Hazard Class:
- 5
- B8
- C2
- D3
Answer: 5. Class 5 covers oxidizers and organic peroxides that can make other materials burn more intensely.
Source: Commercial Driver License Manual — Hazardous materials — hazard classes
2. When parking doubles or triples, avoid spots where you cannot:
- ASee the sunset
- Pull straight through when it is time to leave
- CUse the horn
- DOpen the sleeper
Answer: Pull straight through when it is time to leave. Getting boxed in forces difficult multi-trailer backing in tight lots.
Source: Commercial Driver License Manual — Doubles and triples — parking
3. School bus drivers should practice evacuation procedures:
- AOnly after an actual fire occurs
- BOnly when adults are riding along
- CNever, because drills frighten students
- Early in the school year, with periodic reviews afterward
Answer: Early in the school year, with periodic reviews afterward. Teach every student how exits work and to follow instructions; train older assistants when they are available.
Source: Commercial Driver License Manual — School buses — evacuation planning
4. Escape ramp locations on downgrades are identified by:
- AGPS speed warnings alone
- BNothing; you must memorize every hill
- Highway signs showing where ramps are located
- DOnly CB radio chatter
Answer: Highway signs showing where ramps are located. Use an escape ramp if you lose your brakes—waiting makes the vehicle faster and harder to stop.
Source: Commercial Driver License Manual — Mountain driving — escape ramps
5. What is the minimum tread groove depth allowed on the front wheels of a truck or truck tractor?
- A6/32 of an inch
- B8/32 of an inch
- C2/32 of an inch
- 4/32 of an inch
Answer: 4/32 of an inch. Federal rules require at least 4/32 inch of tread in a major groove on front tires, measured away from tie bars, humps, or fillets.
Source: Commercial Driver License Manual — Vehicle inspection — tires (49 CFR 393.75(b))
CDL knowledge areas
Classes and endorsements, organized.
Each area below scopes the reviewed question bank to one knowledge test. The material is federal, so it applies in California just like everywhere else — the endorsement guide explains how the codes fit together.
The foundation for commercial driving: inspections, space, speed, communication, hazards, and safe operation.
- Pre-trip inspection
- Space and speed management
- Railroad crossings
- Emergency procedures
Understand air-brake components, inspections, warning devices, stopping distance, and controlled braking.
- Dual air systems
- Low-air warnings
- Brake lag and fade
- Applied-leak and static checks
Prepare for safe coupling, inspection, turning, backing, and handling of tractor-trailer combinations.
- Fifth-wheel inspection
- Coupling and uncoupling
- Off-tracking
- Trailer skid prevention
Study hazard communication, shipping papers, placards, loading rules, parking, and emergency response responsibilities.
- Hazard classes
- Placards and labels
- Shipping papers
- Loading and segregation
Learn how liquid surge, outage, bulkheads, and high centers of gravity change vehicle handling.
- Liquid surge
- Outage requirements
- Smooth braking
- Rollover prevention
Practice converter-dolly inspection, coupling order, rearward amplification, and stability principles.
- Coupling sequence
- Converter dollies
- Rearward amplification
- Space management
Prepare to inspect, load, and operate buses while keeping passengers, aisles, and exits safe.
- Vehicle inspection
- Passenger loading
- Emergency exits
- Prohibited practices
Review student loading, danger zones, mirrors, emergency procedures, and special railroad-crossing duties.
- Danger zones
- Student loading
- Mirror use
- Railroad crossings
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Common questions
What this practice can—and cannot—tell you.