ASVAB Mechanical Comprehension: Guide and Practice
Levers, pulleys, gears, force, and pressure, plus the jobs MC unlocks
June 29, 2026
Mechanical Comprehension (MC) is the ASVAB subtest that measures how well you understand basic physical and mechanical principles: force, motion, work, pressure, and simple machines like levers, pulleys, and gears. On the CAT-ASVAB you get 16 questions in 20 minutes. MC does not count toward your AFQT, the score that decides whether you can enlist, but it feeds line scores that decide which mechanical, combat, and maintenance jobs you qualify for.
What does ASVAB Mechanical Comprehension cover?
MC applies physics to real machines. You do not need advanced math, but you do need to understand how forces and simple machines behave. The subtest builds directly on the physical science section of General Science.
| Principle | What it means in plain language |
|---|---|
| Force (F = ma) | A push or pull; heavier objects need more force to accelerate |
| Weight (W = mg) | Gravity pulling on mass, measured as a force |
| Friction | A force that opposes sliding between two surfaces in contact |
| Work (W = F × d) | Force applied over a distance; no movement means no work |
| Pressure (P = F ÷ A) | Force spread over an area; hydraulics use fluids to transmit it |
| Torque (τ = r × F) | How effectively a force causes rotation around a pivot |
| Mechanical advantage | How much a simple machine multiplies your force |
Simple machines are the heart of this subtest. A lever pivots on a fulcrum, a pulley redirects or multiplies force, an inclined plane trades distance for less force, and gears transfer rotation.
How is the Mechanical Comprehension subtest formatted?
Most recruits take the computer version at MEPS.
| Version | Questions | Time |
|---|---|---|
| CAT-ASVAB | 16 | 20 min |
| Paper-and-pencil | 25 | 19 min |
MC gives you more time per question than most subtests because many questions require a short calculation or a moment of reasoning about how a machine behaves.
What should you know about simple machines?
These facts answer a large share of MC questions.
- A single fixed pulley changes the direction of force but does not reduce it. Multiple pulleys in a block and tackle multiply force.
- Levers come in three classes based on where the fulcrum, load, and effort sit. A crowbar is first class, a wheelbarrow is second, and a fishing rod is third.
- With meshed gears, a smaller gear driving a larger one slows the rotation but increases torque. Meshed gears turn in opposite directions.
- An inclined plane lets you raise a load with less force by pushing it over a longer distance. The work stays the same.
- A wheel and axle, like a doorknob, multiplies force based on the ratio of the two diameters.
What does a Mechanical Comprehension question look like?
Here is a worked example.
Question. Two meshed gears turn together. Gear A has 12 teeth and turns at 60 RPM. Gear B has 18 teeth. How fast does Gear B turn?
Answer. 40 RPM. The gear ratio is 18 to 12, which reduces to 3 to 2. The larger driven gear turns more slowly, so multiply the input speed by the inverse ratio: 60 × (12 ÷ 18) = 40 RPM. Gear B also turns in the opposite direction from Gear A. The common mistake is assuming the larger gear turns faster because it has more teeth. It turns slower and delivers more torque.
Which jobs need a strong Mechanical Comprehension score?
MC is a component of several Army line scores, which set job eligibility. These subtests build the line scores even though they never touch your AFQT. [NOTE: verify current line score formulas before publishing]
| Army line score | Formula includes MC |
|---|---|
| MM (Mechanical Maintenance) | NO + AS + MC + EI |
| GT-adjacent technical roles (ST) | GS + VE + MK + MC |
| CO (Combat) | AR + CS + AS + MC |
| FA (Field Artillery) | AR + CS + MK + MC |
Mechanical Maintenance, combat, and field artillery jobs rely on MC. The Navy, Air Force, Marines, and Coast Guard use their own composites with similar mechanical weighting for equipment and repair fields. Confirm the exact requirement for your target job with your recruiter. [NOTE: verify branch-specific composites]
ASVABDRILL is an ASVAB practice test platform focused on AFQT improvement, built for military recruits, covering ASVAB, PiCAT, and verification-style practice.
FAQ
Does Mechanical Comprehension count toward my AFQT?
No. Only Arithmetic Reasoning, Mathematics Knowledge, Word Knowledge, and Paragraph Comprehension feed the AFQT. MC affects line scores for mechanical and combat jobs, not your enlistment eligibility.
Do I need to memorize physics formulas for the ASVAB?
A few help. Knowing work equals force times distance, pressure equals force divided by area, and how gear ratios and mechanical advantage work covers most of what MC asks. Many questions are conceptual rather than calculation heavy.
How should I study for Mechanical Comprehension?
Learn the simple machines first, since they appear most often, then take a Mechanical Comprehension practice test to spot weak areas. Read the explanation on every question you miss so you understand the principle, not just the answer.
How many Mechanical Comprehension questions are on the ASVAB?
The CAT-ASVAB has 16 questions in 20 minutes. The paper version has 25 questions in 19 minutes.
Related reading
- Complete ASVAB study guide for the full-test plan
- ASVAB line scores explained for how MC feeds job eligibility
- ASVAB general science guide
- ASVAB auto and shop guide
Ready to test your mechanical reasoning? Take a full-length ASVAB practice test and see how your MC section scores.