CDL Permit Test: How Many Questions and What Score You Need
The CDL general knowledge test typically has 50 multiple-choice questions, and you need 80 percent correct, 40 of 50, to pass. That’s the base test everyone takes for a commercial learner’s permit. Each endorsement (hazmat, passenger, air brakes, tanker, and the rest) adds its own separate test with its own question count on top of that base test, and the exact numbers are set by each state, not by one federal rule.
The 80 percent passing threshold comes from the AAMVA model that most states build their CDL testing programs around, but the number of questions per section is a state-level decision. We checked the general knowledge count against three state manuals (Texas, California, and Florida) and all three land on 50 questions and 40 correct, but don’t assume every state matches exactly. CDL is the name of a real credential issued by state driver-licensing agencies; this page is not affiliated with any state DMV or FMCSA.
How many questions are on the general knowledge test?
Fifty questions is the number you’ll see in most states, though a handful of states run shorter or longer versions depending on their testing vendor. The Texas Department of Public Safety’s CDL manual sets the general knowledge test at 50 questions drawn from a pool of roughly 250 possible questions, and applicants need 40 correct answers to pass (Texas DPS, Commercial Driver License). California’s DMV Commercial Driver Handbook and Florida’s FLHSMV CDL Handbook both use the same 50-question, 40-correct format for their general knowledge test (California DMV Commercial Driver Handbook; Florida CDL Handbook).
The general knowledge test covers the material every CDL applicant needs regardless of what they’ll drive: safe driving practices, vehicle inspection basics, cargo handling, and basic combination-vehicle awareness. You take it once, and it clears the way for a commercial learner’s permit for whichever class (A, B, or C) you’re applying for.
What score do I need to pass?
You need 80 percent correct on nearly every CDL knowledge test, general knowledge and every endorsement included. On a 50-question general knowledge test, that means 40 correct answers, and missing 11 or more means a retake. The 80 percent threshold holds across the endorsement tests too, just applied to a smaller question count, for example 24 of 30 on the hazmat test in Texas.
Some states charge a retest fee or require a short waiting period after a failed attempt, so check your state’s specific rules before you schedule a first attempt you’re not ready for.
Do all states use 50 questions for the general knowledge test?
Most do, but the count is a state decision, not a federal one, so treat 50 as the common case rather than a guarantee. Federal law under 49 CFR 383 sets what topics states must test and requires an 80 percent passing standard, but it doesn’t fix a question count for any section, which is why exact numbers can shift from state to state (Cornell LII, 49 CFR Part 383, Subpart H). If you’re studying for a state we haven’t listed here, confirm the count on that state’s own CDL manual page before test day.
How do endorsement tests add to the base test?
Each endorsement you want stacks a separate knowledge test on top of the general knowledge test, and some also require a skills test. Want to pull a trailer over 26,001 pounds combined weight? That’s the combination vehicles test. Hauling placarded hazmat? That’s the hazmat test, plus a federal TSA background check that isn’t part of the written exam at all. Driving a bus? That’s the passenger test, and a school bus adds yet another test on top of passenger.
The table below shows the typical question count and passing score for the general knowledge test and each common endorsement, based on the Texas DPS CDL manual, with the 80 percent passing standard confirmed against California and Florida for the general knowledge section. Use it as a study-planning reference, then confirm the exact numbers against your own state’s manual.
| Test section | Typical questions | Passing score (80%) | When you need it |
|---|---|---|---|
| General knowledge | 50 | 40 correct | Every CDL applicant, Class A, B, or C |
| Air brakes | 25 | 20 correct | Any vehicle with air or air-over-hydraulic brakes |
| Combination vehicles | 20 | 16 correct | Class A, pulling a trailer over 10,000 lbs |
| Hazardous materials | 30 | 24 correct | Hauling placarded hazmat (plus a TSA background check) |
| Passenger | 20 | 16 correct | Driving a bus carrying passengers |
| School bus | 20 | 16 correct | Driving a school bus (on top of passenger) |
| Tanker | 20 | 16 correct | Hauling liquid or liquid gas in a permanently mounted or portable tank |
| Doubles/triples | 20 | 16 correct | Pulling two or three trailers |
Source: Texas DPS, Commercial Driver License. Question counts are set by each state; confirm against your own state’s CDL manual before you schedule a test.
Run through a full-length timed set in the CDL Practice Hub CDL practice quiz before you commit to a test date, since knowing the topics is different from answering 50 (or 30, or 20) of them correctly under time pressure.
What happens if I fail a section?
Most states let you retake a failed knowledge test, sometimes the same day, sometimes after a short waiting period, and some charge a retest fee each time. A failed skills test (the road, vehicle inspection, or basic control portions) usually carries a longer required wait, often measured in days rather than hours, because skills retests need a scheduled examiner slot. Check your state DMV’s specific retest policy, since both the wait period and the fee vary.
If a full study packet covering every section in the table above (with practice sets for each) sounds useful, that’s what the CDL Practice Hub CDL permit study guide is built for.
FAQ
Do I need to pass the general knowledge test before I can test for an endorsement? Yes, in every state we checked. The general knowledge test is the base requirement for any CDL class, and endorsement tests are additional, not substitutes.
Is the air brakes test required for everyone? No. You only need it if the vehicle you’ll drive has air brakes or air-over-hydraulic brakes. Skipping it gets you a license restriction that legally bars you from driving air-brake-equipped commercial vehicles.
Can I take multiple endorsement tests on the same day as the general knowledge test? In most states, yes, as long as you pass the general knowledge test first and the testing location has capacity that day. Some smaller testing centers limit how many tests one applicant can take per visit, so call ahead.
Why do practice test websites list different question counts for the same state? Third-party practice sites often quote older manual editions or round the numbers, and states update their manuals periodically. The counts in the table above come from the current state manual we cited; always cross-check against your state’s own current publication before test day.
Does a failed knowledge test show up on my driving record? No. A failed CDL knowledge or skills test is a testing outcome, not a moving violation, and it doesn’t get reported to insurance carriers or appear on your motor vehicle record the way a citation would.