Most guys walk into the IUOE aptitude test cold. They've heard it's "just math" or "not that hard" — then they sit down and realize they haven't done a percent grade calculation since high school. Don't be that guy.
Below is a free sample of exactly what to expect: 5 math questions, 3 mechanical reasoning, and 2 reading comprehension. Every question has the answer and a short explanation so you actually understand the logic, not just memorize it.
Work through these honestly — no calculator unless you'd have one in the test (you won't). See where you're solid and where you need work before test day.
The IUOE limits you to 3 attempts at the aptitude test. Fail three times and you're done — permanently barred from reapplying through that local. This isn't a rumour. It's in the application rules. There's no appeal. Treat every attempt like it counts, because it does.
The math section tests whether you can do the calculations that actually happen on a jobsite — volumes, grades, loads, compaction. No tricks. Pure applied arithmetic.
Q1. A building foundation measures 50 ft long × 40 ft wide × 6 ft deep. How many cubic yards of material need to be excavated?
Q2. A road rises 15 feet vertically over a 250-foot horizontal distance. What is the percent grade?
Q3. A job requires 420 cubic yards of material to be moved. Each truck holds 14 cubic yards. How many truck loads are needed?
Q4. A compaction spec requires 95% Proctor. The maximum dry density from the Proctor test is 116 lbs/cf. What is the minimum acceptable field density?
Q5. A Cat 336 excavator has a 2.5 cy bucket and operates at 80% efficiency. How many cubic yards does it move in 20 passes?
Mechanical reasoning tests whether you understand how machines work — hydraulics, gears, rigging. You don't need to be a mechanic. You need to think like a operator who pays attention.
Q6. A machine's hydraulic system suddenly loses pressure while operating. What is the most likely cause?
Q7. A drive gear has 15 teeth and rotates at 450 RPM. It meshes with a driven gear that has 45 teeth. What is the output RPM of the driven gear?
Q8. A block and tackle system has 3 rope segments supporting a load. The load weighs 1,500 lbs. What is the pulling force required (ignoring friction)?
Reading comp tests whether you can extract specific information from a technical passage. Read carefully — the answer is always in the text.
Passage — Safety Protocol: "A Field Level Risk Assessment (FLRA) must be completed by all workers before beginning any new task or when site conditions change. The FLRA is not optional — it is a regulatory requirement under WorkSafeBC regulations. Workers must document identified hazards, assess the risk level of each hazard, and confirm controls are in place before proceeding. A supervisor must sign off on any FLRA where a hazard is rated High risk. Copies must be retained on site for a minimum of three years."
Q9. According to the passage, when is a supervisor sign-off required on an FLRA?
Passage — Pre-Trip Inspection: "Operators are required to complete a pre-trip inspection before operating any piece of heavy equipment. If a deficiency is identified during inspection, the operator must tag the machine out of service using the appropriate lockout/tagout procedure and notify their supervisor immediately. The machine must not be operated until the deficiency has been repaired and cleared by a qualified mechanic. Operators who operate tagged-out equipment are subject to disciplinary action and may be held personally liable for any resulting incidents."
Q10. What must an operator do if they find a deficiency during a pre-trip inspection?
8–10 correct: You're in solid shape. Review any you missed and go into test day confident.
5–7 correct: Workable, but you have gaps. Spend time on the section that tripped you up.
Under 5: Don't walk into the real test yet. You've got work to do — and you only get 3 shots.
For a deeper drill, check out our full IUOE aptitude test practice guide and the how to pass the IUOE test breakdown — both go deeper into what the test actually looks like and how to prepare for each section.
The full Dirt School IUOE Study Guide has 40 practice questions across all sections — math, mechanical, reading comprehension — plus explanations, study tips, and a breakdown of exactly what each section of the real test covers.
Get the Full 40-Question Guide →Master the formulas, definitions, and quick-reference guides used on every jobsite. Free 10-minute cram sheet + email updates.
✓ Instant PDF download | ✓ No spam | ✓ Used by 1,000+ operators