How Many Questions Are on the CDL Permit Test? General Knowledge, Air Brakes & Endorsements by State
Short answer: unlike regular car permit tests—which vary from 18 to 50 questions by state—commercial driver’s license (CDL / CLP) knowledge tests are governed by a federal standard. Under FMCSA regulation 49 CFR § 383.133(c)(6), every US state must require a minimum passing score of 80% on each CDL knowledge test module, and the General Knowledge test must contain at least 30 items (50 questions in the standard AAMVA state model, requiring 40 correct to pass).
Explore all 21,787 published CDL questions across 51 US jurisdictions on our National CDL Practice Test Hub.
CDL knowledge test modules, standard lengths & our national question bank
Which CDL knowledge tests you take depends on the vehicle group (Class A, B, or C), whether the vehicle has air brakes, and which endorsements (H, N, P, S, T, X) you apply for. Every module is scored independently at an 80% pass mark:
| CDL Test Module / Endorsement | CFR / Code | Standard Exam Qs | 80% Pass Score | Questions in Our Bank |
|---|---|---|---|---|
| General knowledge | Core (All Classes A/B/C) | 50 | 40 / 50 (80%) | 1,290 |
| Combination vehicles | Class A Combination | 20 | 16 / 20 (80%) | 249 |
| Hazardous materials | H Endorsement | 30 | 24 / 30 (80%) | 246 |
| Air brakes | L Restriction Removal | 25 | 20 / 25 (80%) | 235 |
| Passenger | P Endorsement | 20 | 16 / 20 (80%) | 168 |
| School bus | S Endorsement | 20 | 16 / 20 (80%) | 81 |
| Doubles/triples | T Endorsement | 20 | 16 / 20 (80%) | 43 |
| Tank vehicles | N Endorsement | 20 | 16 / 20 (80%) | 26 |
Top 20 state CDL practice question banks (of 51 US jurisdictions)
Because most states base their Commercial Driver’s Manual on the AAMVA model manual, 1,020 of the 2,338 distinct CDL questions in our database appear in 10 or more state banks, while 316 questions are unique to a single state. Pick your state below or view all 51 jurisdictions on the US CDL Practice Test hub:
| State | Total CDL Qs | General Knowledge | Vehicle / Air Brakes | State-Unique Qs | Start State CDL Practice |
|---|---|---|---|---|---|
| Utah | 477 | 249 | 196 | 7 | Practice (477 Q) |
| Nebraska | 476 | 250 | 213 | 6 | Practice (476 Q) |
| Tennessee | 468 | 256 | 205 | 3 | Practice (468 Q) |
| Connecticut | 466 | 262 | 200 | 2 | Practice (466 Q) |
| Arkansas | 464 | 240 | 197 | 3 | Practice (464 Q) |
| Mississippi | 463 | 259 | 216 | 3 | Practice (463 Q) |
| Oregon | 463 | 254 | 190 | 2 | Practice (463 Q) |
| New Hampshire | 461 | 250 | 204 | 2 | Practice (461 Q) |
| Maryland | 460 | 255 | 207 | 5 | Practice (460 Q) |
| North Carolina | 460 | 226 | 195 | 2 | Practice (460 Q) |
| South Dakota | 460 | 242 | 206 | 5 | Practice (460 Q) |
| Wyoming | 459 | 236 | 213 | 3 | Practice (459 Q) |
| Minnesota | 458 | 289 | 198 | 21 | Practice (458 Q) |
| Nevada | 457 | 257 | 190 | 2 | Practice (457 Q) |
| Alabama | 447 | 234 | 190 | 0 | Practice (447 Q) |
| Illinois | 447 | 240 | 193 | 21 | Practice (447 Q) |
| South Carolina | 447 | 235 | 197 | 5 | Practice (447 Q) |
| Delaware | 443 | 225 | 185 | 1 | Practice (443 Q) |
| Wisconsin | 443 | 224 | 186 | 2 | Practice (443 Q) |
| New Jersey | 438 | 226 | 190 | 6 | Practice (438 Q) |
Steps to earn your Commercial Learner’s Permit (CLP)
- Obtain DOT Medical Examiner's Certificate (Med Card)
- Study your state's CDL Manual (General Knowledge, Air Brakes, Combination)
- Score 80%+ on each required CDL knowledge test module
- Complete Entry-Level Driver Training (ELDT) theory if applicable
- Hold your CLP for at least 14 days before the CDL skills/road test
Frequently asked questions (CDL Permit Test)
What is the federal passing score for all CDL permit (CLP) knowledge tests?
Under federal FMCSA regulations (49 CFR § 383.133(c)(6)), every state must require applicants to answer at least 80 percent of the questions correctly on each CDL knowledge test module (General Knowledge, Air Brakes, Combination Vehicles, and endorsements).
How many questions are on the CDL General Knowledge, Air Brakes, and Endorsement tests?
Under the AAMVA CDL testing model used by US state DMVs, the core CDL General Knowledge exam typically has 50 questions (40 correct to pass, 80%), Air Brakes has 25 questions (20 to pass), Combination Vehicles has 20 questions (16 to pass), Hazardous Materials (H) has 30 questions (24 to pass), Passenger (P) and Tanker (N) have 20 questions (16 to pass), and School Bus (S) and Doubles/Triples (T) have 20 questions (16 to pass).
How many CDL practice questions are in the License Test national dataset?
Our national CDL dataset contains 21,787 total published questions (2,338 distinct wordings) across 51 US state banks (all 50 states + Washington DC).
Can I take the CDL knowledge test in a language other than English?
Federal rules (49 CFR § 383.133) restrict interpreter use and several states (for example, Texas DPS since June 1, 2026 and Florida FLHSMV since February 6, 2026) administer CDL/CLP knowledge exams in English only. Check your state DMV page before booking.
Official federal & state CDL references
- eCFR — 49 CFR § 383.133 Test Methods (80% minimum passing score on CDL knowledge tests) (checked 2026-10-24)
- FMCSA — Commercial Driver’s License Program Overview (checked 2026-10-24)
- Texas DPS — Changes to CDL Knowledge Testing (checked 2026-10-17)
- License Test — US CDL Practice Test Hub (All 51 Jurisdictions)