How Many Questions Are on the CDL Test? (2026)

The CDL General Knowledge test has 50 multiple-choice questions, and you need 40 right to pass. Every other CDL written test is shorter, usually 20 to 30 questions, and each one also needs 80%.

Which tests you take depends on the license class you want and the vehicle you will drive. Here is the lineup as Washington State's Department of Licensing lists it.

Test	Who takes it	Questions	To pass
General Knowledge	Everyone	50	40
Air Brakes	Anyone driving a vehicle with air brakes	25	20
Combination Vehicles	Class A applicants	20	16
Hazardous Materials	Hazmat endorsement	30	24
Tanker	Tanker endorsement	20	16
Passenger	Bus drivers	20	16
School Bus	School bus drivers	20	16
Doubles/Triples	Pulling double or triple trailers	20	16

Federal rules set the 80% passing score. States write and run their own tests, so your state may use a different question count. Some states do not publish counts at all. Minnesota's DPS, for one, does not list question counts for most CDL tests. Check your state's CDL manual and DMV page before test day.

How many can you miss?

On General Knowledge, you can miss 10. On Air Brakes, 5. On a 20-question test, 4. That room disappears fast if you guess on a whole topic. Study your weakest topics first. That beats taking test after test.

How long do you get?

States set their own time limits. Look on your state DMV page or ask the exam station when you book. Do not guess the time limit. Plan to finish with time to spare.

Do you take them all on the same day?

Usually you can spread them out. Many Class A drivers take General Knowledge, Air Brakes and Combination Vehicles first, then add endorsements later. Each test is scored on its own.

What a typical Class A driver takes

General Knowledge (50), Air Brakes (25) and Combination Vehicles (20). On the Washington counts, that is 95 questions. You need 80% on each test, not 80% overall. Read more in which CDL tests you need.

Ready to try some questions? Here are 10 exam-style questions built from the official CDL manual.

For the full list of free tests, go to CDL practice tests. You can also work on the Air Brakes practice test or the Combination Vehicles practice test.

Find out your score in 10 minutes

Take the free Diagnostic. You get a predicted score and your three weakest topics.

Common questions

Are the questions the same in every state?

The topics come from a national model CDL manual, so they are very similar everywhere. Wording, question counts for a few tests, and state sections can differ. Always check your own state's CDL manual and DMV page.

What happens if I fail a CDL written test?

Rules vary by state. Minnesota, for example, lets you try each knowledge test once per day, and charges a fee on the third and later written tests. Check your state DMV page for waiting periods and fees.

How do I know I'm ready for the CDL written test?

A good sign is scoring 85% or higher on three full practice tests in a row, because the real cutoff is 80%. The FirstTry CDL Readiness Score tracks this for you.

Do I need 80% overall or on each test?

On each test separately. Federal rule 49 CFR 383.135 says you must answer at least 80 percent of the questions correctly on each knowledge test.