FMCSA / State Driver Licensing Agencies

CDL Class A

Commercial Driver's License Class A Knowledge Test

The knowledge test battery required to earn a commercial learner's permit and Class A CDL — the license needed to drive tractor-trailers and other combination vehicles. Administered by state licensing agencies under federal FMCSA standards.

Varies by state; untimed or generously timed in most statesRequired to practice

What's on the exam

FMCSA CDL knowledge test standards (49 CFR Part 383)

General Knowledge

40%

Vehicle inspection basics · Basic vehicle control · Shifting and managing space · Seeing hazards and communicating · Driving in adverse conditions · Cargo handling and weight distribution

Air Brakes

20%

Air brake system components · Dual air brake systems · Inspecting air brake systems · Using air brakes and braking distance · Spring (parking/emergency) brakes

Combination Vehicles

20%

Coupling and uncoupling · Driving combination vehicles safely · Rollover and rearward amplification · Trailer air lines and glad hands · Inspecting combination vehicles

Pre-Trip Inspection & Safety

20%

Seven-step inspection method · Engine compartment checks · Brakes, tires, and suspension checks · Lights, reflectors, and emergency equipment · In-trip and post-trip inspection

Frequently asked questions

How much does the CDL Class A cost?

Fees vary. Permit, testing, and licensing fees vary by state.

How long is the CDL Class A and how many questions does it have?

General Knowledge typically 50 questions; Air Brakes and Combination Vehicles typically 20–25 each — Varies by state; untimed or generously timed in most states.

What do you need to pass the CDL Class A?

80% on each knowledge test.

Can you retake the CDL Class A?

Varies by state; typically allowed after a short waiting period with a retest fee.

What is the best way to study for the CDL Class A?

Study the official blueprint, not random material: the exam is weighted by domain (General Knowledge 40%, Air Brakes 20%, Combination Vehicles 20%, Pre-Trip Inspection & Safety 20%). Spaced-repetition flashcards built domain-by-domain against that blueprint are the most time-efficient way to cover everything the exam tests.

Program in development

We're building a blueprint-complete program for this exam. Meanwhile, explore live programs across 7 exam.

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