What Does a Mechanical Engineer Do?
A chiller that quits during an August heat wave is the kind of problem a mechanical engineer gets called in to solve. Working from engineering offices for manufacturers, consulting firms, government agencies and large facilities teams, mechanical engineers design, test and improve machines and the heating, cooling and pumping systems inside buildings. Visits to plant floors and job sites are part of the routine.
Also known as: Senior Mechanical Engineer, Mechanical Engineer Associate
Mechanical Engineer Duties and Responsibilities
The primary responsibilities of a mechanical engineer include:
- Design machines, components and building systems in CAD software such as SolidWorks or AutoCAD.
- Calculate heating and cooling loads, airflow and pipe sizes for new and renovated buildings.
- Build and test prototypes, then revise the design based on measured performance.
- Prepare drawings, specifications and cost estimates for construction bids and manufacturing runs.
- Review contractor submittals and shop drawings against the design and the applicable codes.
- Investigate equipment failures and recommend repair, replacement or a change in design.
- Inspect installed equipment on site and confirm it performs as specified before handover.
- Evaluate energy use in existing buildings and propose upgrades that lower operating costs.
- Coordinate with electrical, structural and controls engineers so every system fits and works together.
- Supervise drafters and junior engineers and check their calculations before drawings are issued.
Required Skills and Qualifications
To succeed as a mechanical engineer, you will need the following skills and qualifications:
- SolidWorks, AutoCAD or Inventor for models and drawings
- Thermodynamics, fluid mechanics and heat transfer
- HVAC design and mechanical building codes
- Finite element analysis for stress, heat and vibration
- Professional Engineer (PE) license for roles that seal drawings
- Clear technical writing for specifications and reports
- Patient, methodical troubleshooting when equipment fails
- Coordination with contractors, vendors and other engineers
Education and Training
Most mechanical engineers qualify through a bachelor's degree in mechanical engineering, but some start out by working as drafters or engineering technicians while they finish the degree part-time. Once you have passed the Fundamentals of Engineering exam and built up supervised experience you will need to pass the PE exam in the state where you plan to seal drawings. A license matters most in consulting.
Salary and Job Outlook
Typical pay: $84,130 - $132,590 per year, with a median of $104,110.
The range covers the middle half of earners nationwide. Source: U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics, May 2025, Mechanical Engineers.
BLS projects employment of mechanical engineers to grow about 11 percent from 2025 to 2035. Demand will come from several directions, including factory automation; energy upgrades to buildings, such as heat pumps and better ventilation; and electric vehicles, as carmakers redesign drivetrains and battery cooling. The same projection allows for roughly 17,800 openings a year, so a new graduate with co-op or internship experience should find steady interest from employers.
Outlook source: U.S. Bureau of Labor Statistics, Employment Projections, 2025 to 2035, Mechanical engineers.