How Many Questions Are on the CDL Test?
The short answer: it depends on which class of CDL you want and which endorsements you're adding. The CDL written exam isn't one test — it's a series of separate tests, and the total question count you face is simply the sum of every section that applies to you.
This guide breaks down the exact question count and passing score for every section, explains why your total can range anywhere from 50 to over 150 questions, and includes a calculator so you can find your exact number before you walk into the DMV.
The number everyone needs to know first: Every section requires 80% to pass, no exceptions. A 50-question test means 40 correct. A 20-question test means 16 correct. There's no rounding down.
The core test sections — question count by section
These are the standard FMCSA-aligned section counts used by most states. Some states adjust slightly — always verify with your own state's CDL manual — but these numbers are correct for the large majority of test takers.
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Based on standard FMCSA-aligned section counts. Your state may vary slightly — confirm with your local DMV manual.
Why your total isn't one number
Most people picture the CDL exam as a single test with a single question count. It isn't. It's a stack of independent tests, and you only face the ones that apply to the license and endorsements you're pursuing.
- Every applicant takes General Knowledge — 50 questions, the foundation for every class and every endorsement path.
- Class A adds Combination Vehicles — 20 more questions, since Class A involves towing heavy trailers that Class B does not.
- Almost everyone takes Air Brakes — 25 questions. Skip it and your CDL gets an L restriction blocking you from driving any vehicle with air brakes, which is most commercial trucks.
- Each endorsement is its own separate test — Hazmat, Tanker, Passenger, School Bus, and Doubles/Triples each add their own question count on top of the base requirement.
This is why a Class A applicant going for Air Brakes plus Hazmat plus Tanker faces a very different total than a Class B applicant with no endorsements — 145 questions versus 75, even though both are getting a CDL.
Common total combinations
| Path | Sections included | Total questions |
|---|---|---|
| Class B, no endorsements | General Knowledge + Air Brakes | 75 |
| Class A, no endorsements | General Knowledge + Air Brakes + Combination Vehicles | 95 |
| Class A + Tanker | Above + Tanker | 115 |
| Class A + Hazmat | Above + Hazmat | 125 |
| Class A + Hazmat + Tanker (X) | Above + both | 145 |
| Class B + Passenger + School Bus | General Knowledge + Air Brakes + Passenger + School Bus | 115 |
The smart move: Take every test you plan to ever need in one DMV visit. Most states let you take multiple knowledge tests on the same application — sometimes the same fee covers all of them. Showing up once prepared for General Knowledge, Air Brakes, Combination Vehicles, Tanker, and Hazmat all together costs almost nothing extra in time, but saves you multiple separate DMV trips later.
The 80% rule — and why it matters more than the total
The total question count gets attention, but the passing threshold is what actually determines whether you walk out with a permit. Every single section — no exceptions, no averaging — requires 80% correct.
- You cannot average sections together. Scoring 95% on General Knowledge does not offset a 70% on Air Brakes. Each test is pass or fail entirely on its own.
- Smaller tests leave less room for error. On the 50-question General Knowledge test, you can miss 10 and still pass. On a 20-question endorsement test, you can only miss 4.
- Failing one section doesn't fail the others. If you pass General Knowledge and Air Brakes but fail Combination Vehicles, you keep your passes on the first two and only need to retake the one you missed.
Don't underestimate the shorter tests: A 20-question endorsement test feels easier because there's less material — but the margin for error is tighter. Missing 5 questions fails a 20-question test (75%) while the same 5 misses on a 50-question test still passes (90%). Study the shorter endorsement sections just as seriously as General Knowledge.
Does the question count vary by state?
Slightly, yes. The FMCSA sets federal baseline requirements that every state must meet, but individual states have some flexibility to adjust the exact count. Most states use the standard 50/25/20 structure described above. A few states — California is a commonly cited example — sometimes use up to 60 questions on General Knowledge to cover additional state-specific content.
The 80% passing threshold, however, is fixed everywhere. No state can lower it. Whatever the total question count in your state, the standard for passing never drops below 80% on any section.
Always check your own state's official CDL manual for the exact number before test day. We've covered state-specific details for Texas, California, Florida, and New York if you're testing in one of those states.
What's actually being tested in each section
Knowing the count is useful for planning. Knowing what's inside each test is what actually gets you a pass.
- General Knowledge: Safe driving practices, vehicle inspection procedures, basic vehicle control, cargo securement, and federal regulations including hours of service and drug/alcohol policy.
- Air Brakes: Air brake system components, PSI numbers, warning devices, and the correct inspection sequence. Full breakdown: CDL Air Brakes Test Explained.
- Combination Vehicles: Coupling and uncoupling, trailer dynamics, and rollover prevention specific to towing heavy trailers.
- Hazmat: Hazard classes, placarding, shipping papers, and emergency procedures. Full breakdown: CDL Hazmat Endorsement Study Guide.
- Tanker: Liquid surge, tank types, and rollover risk specific to partially filled tanks. Full breakdown: CDL Tanker Endorsement Guide.
For the complete picture of every endorsement, what each one authorizes, and how they pair together for specific careers, see CDL Endorsements: Complete List and Guide.
Ready to study for whichever sections you need?
PassMyCDL's free lessons cover General Knowledge and Air Brakes. The Hazmat and Tanker packs cover their full test content with structured video lessons and practice questions.
CDL Test Question Count FAQ
How many questions are on the CDL General Knowledge test?
50 questions in most states. You need 40 correct — an 80% passing score — to pass. Required for every CDL applicant regardless of class.
How many total questions are on a Class A CDL test?
Typically 95 questions total: 50 General Knowledge + 25 Air Brakes + 20 Combination Vehicles. Adding endorsements increases this — each has its own separate test.
How many total questions are on a Class B CDL test?
Typically 75 questions total: 50 General Knowledge + 25 Air Brakes. Class B skips Combination Vehicles since it doesn't involve towing large trailers.
Does the number of questions vary by state?
Slightly. The FMCSA sets federal baselines, but states can adjust counts somewhat — some states use up to 60 questions for General Knowledge. The 80% passing threshold never changes regardless of state.
Can you average your score across multiple test sections?
No. Each section is scored independently and requires 80% on its own. A strong General Knowledge score cannot offset a weak Air Brakes score — you must pass every section separately.
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