What's the Passing Score on the Tennessee CDL General Knowledge Test?
You need 40 out of 50 correct — 80% — to pass Tennessee's CDL general knowledge test. That figure comes from federal regulation, not TDOSHS, so it's the same number used almost everywhere in the country.
Where the 80% figure actually comes from
49 CFR Part 383 sets both the question count and the passing percentage for the CDL general knowledge test nationwide, unlike Tennessee's own regular permit test, which has a state-set 60-minute time limit alongside its 80% threshold.
A missed attempt costs more than just your time — a Tennessee CLP runs $14 (Class A) or $13 (Class B/C) and is only good for 12 months.
Building in a safety margin
Treat 80% as a floor, not a target — aim for 90%+ across all 17 topic areas in practice, since a real exam under time pressure tends to run a few points below your practice average.
Our practice tests break your score down by topic immediately after each set, so a weak spot doesn't stay hidden inside an otherwise decent overall percentage.
The parts of the test that pull scores down
Air brake systems and hours-of-service limits are the two topics most likely to cost points, since both hinge on exact numbers (PSI thresholds, hour caps) rather than driving intuition.
Cargo securement sequencing is another common miss — remembering that the first check happens within 50 miles, then every 150 miles or 3 hours after, is easy to get backwards under pressure.
Read the explanation on every practice question, correct or not — it's what actually closes these gaps, not just re-answering until you get lucky.
Frequently Asked Questions
Can Tennessee require a higher passing score than 80%?
No. 49 CFR Part 383 fixes the CDL general knowledge test at 50 questions and an 80% passing threshold nationwide — TDOSHS administers that federal standard rather than setting its own.
Does the CDL test have the same 60-minute time limit as the regular permit test?
Tennessee's published 60-minute limit applies to the regular permit test; the CDL knowledge test's timing follows the same federal framework as its question count and passing score. Confirm current procedures with TDOSHS.
What score should I aim for on practice tests?
Aim for 90% or higher consistently before your appointment. That buffer above the 80% minimum accounts for first-attempt nerves and any last-minute rule changes.
Ready to put this into practice?
Start a free Tennessee cdl practice testLast reviewed: 2026-07-20