How many questions are on the Ohio CDL General Knowledge test?

50 questions. You must answer at least 40 correctly (80%) to pass. This test is required for every CDL applicant regardless of class or endorsement.

How many questions are on the Ohio CDL Combination Vehicles test?

20 questions, requiring 16 correct (80%) to pass. Required for Class A CDL applicants who will operate combination vehicles.

What language are Ohio CDL knowledge tests given in?

English only. Ohio does not currently offer CDL knowledge testing in Spanish or any other language.

What happens if I fail an Ohio CDL knowledge test?

You can retake it at a BMV Deputy Registrar location. Confirm current retest wait times and fees directly with your local Deputy Registrar, since these can vary.

Ohio CDL Test Questions 2026: What Each Test Covers

Q: How many questions are on the Ohio CDL Air Brakes test?

25 questions, requiring 20 correct (80%) to pass. Required if your vehicle has air brakes, including air-over-hydraulic systems. Skipping or failing it results in a restriction on your CDL.

All three Ohio CDL knowledge tests use the same 80% passing threshold, but the question counts and stakes for skipping each one differ meaningfully. Here's exactly what to expect on each.

General Knowledge Test

50 Questions 40 to Pass (80%) Required for All Applicants

Covers vehicle inspection, basic vehicle control, driving safety, cargo transport, hazardous materials awareness, night driving and adverse conditions, emergency procedures, speed management, and Ohio-specific rules. Required for every CDL applicant, regardless of class or endorsements.

Air Brakes Test

25 Questions 20 to Pass (80%) Required for Air Brake Vehicles

Covers air brake system basics, dual air brake systems, inspecting air brakes, using air brakes correctly, spring brakes and parking brakes, and malfunctions/emergencies. Required if your vehicle has air brakes, including air-over-hydraulic systems.

Skipping or failing this test results in a restriction on your CDL — preventing you from operating any air brake-equipped commercial vehicle until you pass it.

Combination Vehicles Test

20 Questions 16 to Pass (80%) Required for Class A

Covers coupling and uncoupling, inspecting combination vehicles, off-tracking and steering, rollover prevention, skid control and jackknifing, doubles and triples, and antilock brakes. Required for Class A CDL applicants operating tractor-trailer combinations.

Testing Language

Ohio CDL knowledge tests are administered in English only. This applies to both the knowledge tests and the skills test, with no Spanish-language option currently available for CDL testing.

Retest Rules

If you fail a knowledge test, you can retake it at a BMV Deputy Registrar location. Retest wait times and fees can vary — confirm current specifics directly with your local Deputy Registrar before your retest attempt.

Practice All 3 Tests Free

500 real practice questions across General Knowledge, Air Brakes, and Combination Vehicles.

Start Ohio CDL Practice Tests Full CDL Process Guide

Frequently Asked Questions

How many questions are on the General Knowledge test?

50 questions, 40 correct (80%) needed to pass. Required for every applicant.

How many questions are on the Air Brakes test?

25 questions, 20 correct needed. Skipping it restricts you from air brake vehicles.

How many questions are on the Combination Vehicles test?

20 questions, 16 correct needed. Required for Class A applicants.

What happens if I fail?

You can retake it at a Deputy Registrar location — confirm current wait times and fees locally.