What's the Passing Score on the Colorado CDL General Knowledge Test?
40 out of 50 — 80% — passes Colorado's CDL General Knowledge test. That figure comes from federal regulation, applied identically here as it is in every other state, regardless of what Colorado's own regular permit test requires.
A federal number, not a DMV one
49 CFR Part 383 sets both the question count and the 80% passing percentage for the CDL general knowledge test nationwide — the Colorado DMV administers that standard rather than writing its own.
A missed attempt costs more than just your time: Colorado's CLP is a one-time, non-renewable permit valid for a year, so a failed knowledge test still means scheduling a retest before training can properly begin.
Building in a safety margin
Treat 80% as a floor, not a target — aim for 90%+ across all 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 Colorado require a higher passing score than 80% for the CDL test?
No. 49 CFR Part 383 fixes the CDL general knowledge test at 50 questions and an 80% passing threshold nationwide — the DMV administers that federal standard rather than setting its own.
Does Colorado's CLP expire faster if I fail the knowledge test first?
The CLP itself is only issued after passing the required knowledge tests, so a failed attempt just delays issuance — it doesn't shorten the eventual one-year validity period.
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 Colorado cdl practice testLast reviewed: 2026-07-21