What to Study First for the CDL Permit Test

Study General Knowledge first, Air Brakes second, and endorsements last. Move from one block to the next when your practice score says so, not when the calendar does. By the end of this page you will have a three-week order, a formula for your own pass mark, and a gate to clear before each move.

Start with General Knowledge because every other test builds on it

General Knowledge is the foundation test for every CDL applicant, and it is the largest of the written tests, according to Union Test Prep. Everything else you study sits on top of it.

It covers two big areas: driving safely and transporting cargo safely, per CDL Study Buddy's 2026 guide. Driving safely includes vehicle inspection, basic control, speed and space management, hazard awareness, emergency moves, skid control and railroad crossings. Cargo covers inspection, weight and balance, and securing the load.

Here is how to work through it:

1. Read each section of your state's CDL manual twice. The first read is for the big picture. The second read is for the numbers and the exact words.
2. Write short notes as you go. One line per rule is enough.
3. At the end of the block, take a General Knowledge practice test and check your score against the gate below.

If the manual language is slowing you down, the plain-English tips in the guide on studying the CDL manual when it is hard to read will save you time.

Study Air Brakes second and give it more time per page

Air Brakes is shorter than General Knowledge, but the material is dense, and many test takers find it the hardest section, as Sage Schools notes. Plan on roughly twice the study time per page that you gave General Knowledge. Only trim that if your diagnostic shows Air Brakes is already one of your strong areas.

Do not read it like a story. Learn one part of the system at a time, then test yourself on that part before you add the next one. If you want a day-by-day version, the 7-day Air Brakes plan lays it out.

Add Combination Vehicles only if you want a Class A permit

For an unrestricted Class A permit to train on a tractor-trailer, most applicants need three tests: General Knowledge, Combination Vehicles and Air Brakes, as Sage Schools lists. If you are going for Class A, put Combination Vehicles in the same week as Air Brakes. If you are not, skip it and use the time on review.

Your state decides the exact list of tests for each class. Check your state CDL manual before you plan.

Leave endorsements for last, and only the ones your job needs

Endorsements are extra tests for certain vehicles or cargo: Tank Vehicles, Doubles/Triples, Passenger, School Bus and Hazardous Materials, per Sage Schools. They are not part of the base tests.

Here is the rule: when your job or your first employer does not need an endorsement, do not study for it yet. Pass the base tests first. Every hour you spend on Hazmat before General Knowledge is solid is an hour taken from a test you must pass.

When you do need one, this list of every endorsement and its test shows what each one covers.

Run a three-week order and clear a gate before each move

A common plan runs three weeks in this order: General Knowledge in week 1, the harder topics such as Air Brakes and Combination Vehicles in week 2, and full timed practice tests with review in week 3, as CDL Study Buddy lays out. The order is sound. What most plans leave out is how you know it is time to move on.

Add a gate after each block:

Here is the line I would tape to your wall: do not move on because the calendar says so. Move on when your practice score says so.

Short on time? Keep the same order and shrink each block. Do not cut the timed practice and review block. If you only have an hour a day, the schedule for studying with a full-time job fits the same order into small pieces.

Work out your own pass mark before the first practice test

Guides list the passing score as 80 percent, and questions come from your state's CDL manual, according to CDL Study Buddy. Question counts and time limits differ by state, so do not trust any single number from a website. Use your state's manual.

Then run two quick calculations.

Questions you must get right = total questions x 0.80, rounded up.

Your miss budget = total questions minus the number you must get right.

Example: say your state's General Knowledge test has 50 questions. You need 40 right, so your miss budget is 10. Your gate for week 1 is a practice score that stays at 40 or better out of 50, not once but on repeat tries. Use your own state's numbers in place of the example.

Three mistakes that cost you a retest

A miss can mean a waiting period before your next try, as CDLSchool.com explains, and retake rules and waiting times are set state by state, per Drive Big Trucks. You also pay a fee for another try in most places. So these three mistakes cost real days and real money:

• Moving on by date. Weak spots from week 1 follow you into week 2 and show up again on test day.
• Skipping the timed practice week. You know the content but not the pace. Check your state manual for the time limit.
• Skipping the review of missed questions. The same topics get missed again. Retry each missed question after 1 day, 3 days and 7 days. FirstTry CDL's Mistake Fixer re-drills misses on that same 1, 3 and 7 day schedule, and a paper list works too.

Copy this: the three-week study gate checklist

Keep this on your phone.

Before you start

• I found my state's CDL manual
• I wrote down my state's question count, passing score and retake rule
• I worked out my pass mark and my miss budget
• I know which tests my class needs (Class A: General Knowledge, Combination Vehicles, Air Brakes)

Week 1: General Knowledge

• Read every section twice and took short notes
• Took a practice test
• Score is above my pass mark on two tries in a row

Week 2: Air Brakes (and Combination Vehicles for Class A)

• Learned one part of the air brake system at a time
• Practiced a few questions every day
• Air Brakes score is above my pass mark

Week 3: Drill

• Took full practice tests with a timer
• Reviewed every missed question
• Retried misses after 1, 3 and 7 days
• Scores stay above my pass mark on repeat tries

After that

• Studied only the endorsements my job needs, one at a time
• Passed the same gate for each one
• Booked my test

If you work through this and still miss questions that look right but are incomplete, the guide on why you keep failing practice tests covers what to change. This guide adds the study order and the gates. That guide covers the misses.

Do this in the next ten minutes

Open your state's CDL manual and write down three things: the number of questions on the General Knowledge test, the passing score, and the retake rule. Then work out your pass mark with the formula above. That one note tells you what number you are aiming at.

Check where you stand before you pick a first week

The order above works for most new drivers. The free diagnostic tells you which of your areas are weak, so you can adjust it. It takes about 10 minutes, needs no account, and shows a predicted score and your weak spots. State rules differ, and FirstTry CDL is not affiliated with any DMV, FMCSA or government agency, so keep your state manual open next to it. Take the free diagnostic.