The Engineering Knowledge Platform

Free Engineering
Tools & Exam Prep

Engineering learning studios, one hub per discipline. Each combines design tools, 3D web apps, technical articles, and downloadable references — everything you need, organized by the work you do.

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Browse by discipline, by the software you use, or by the task you're trying to get done.

About Engineers Universe

Knowledge Grows
When It’s Shared.

Engineers Universe is built by engineers, educators, and technology professionals dedicated to making engineering, science, technology, and AI knowledge more accessible, visual, and practical.

Explore interactive learning studios, 3D models, simulations, engineering tools, technical resources, books, and applications — all designed to help you learn, grow, and succeed.

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Interactive Learning
Studios, 3D viewers, simulations, and engineering tools — organized by discipline.
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Free Forever
Every resource — studios, tools, books, and content — is provided at no cost.
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Visual & Practical
3D experiences, interactive schematics, and real-world design tools built for learners.
🇺🇸
US-Based Professionals
Developed and maintained by experienced professionals committed to quality.

Join us in sharing knowledge, inspiring innovation, and helping others learn.

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🎓 Engineering Learning Studios

Pick Your Discipline

Design tools, 3D viewers, articles, and downloads — all organized by engineering discipline.

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Fire Alarm Systems2 Live
Design Tools · 3D Apps · Articles · Downloads
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HVAC Systems1 Live
Design Tools · 3D Apps · Articles · Downloads
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Electrical Systems2 Live
Design Tools · 3D Apps · Articles · Downloads
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Radio Communications1 Live
Design Tools · 3D Apps · Articles · Downloads
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Mechanical Systems1 Live
Design Tools · 3D Apps · Articles · Downloads
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Enterprise IT Networks1 Live
Design Tools · 3D Apps · Articles · Downloads
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AI Studio1 Live
Design Tools · 3D Apps · Articles · Downloads
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Plumbing Systems1 Live
Design Tools · 3D Apps · Articles · Downloads
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Fire Suppression1 Live
Design Tools · 3D Apps · Articles · Downloads
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Geotechnical Engineering1 Live
Design Tools · 3D Apps · Articles · Downloads
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Structural Engineering1 Live
Design Tools · 3D Apps · Articles · Downloads
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Civil & Site Engineering1 Live
Design Tools · 3D Apps · Articles · Downloads
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SCADA & Industrial Controls1 Live
Design Tools · 3D Apps · Articles · Downloads
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Cybersecurity & OT Security1 Live
Design Tools · 3D Apps · Articles · Downloads
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Smart Buildings1 Live
Design Tools · 3D Apps · Articles · Downloads
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Renewable Energy1 Live
Design Tools · 3D Apps · Articles · Downloads
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Physical Security1 Live
Design Tools · 3D Apps · Articles · Downloads
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Software Engineering1 Live
Design Tools · 3D Apps · Articles · Downloads
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BIM, CAD & Digital Design1 Live
Design Tools · 3D Apps · Articles · Downloads
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Industrial & Systems Engineering1 Live
Design Tools · 3D Apps · Articles · Downloads
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Chemical & Process Engineering1 Live
Design Tools · 3D Apps · Articles · Downloads
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Environmental & Water Resources1 Live
Design Tools · 3D Apps · Articles · Downloads
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Materials Science & Metallurgy1 Live
Design Tools · 3D Apps · Articles · Downloads
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Aerospace Engineering1 Live
Design Tools · 3D Apps · Articles · Downloads
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STEM Learning Studio1 Live
Design Tools · 3D Apps · Articles · Downloads
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Engineering Software1 Live
Design Tools · 3D Apps · Articles · Downloads
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Robotics & Automation1 Live
Design Tools · 3D Apps · Articles · Downloads
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Semiconductor & Electronics1 Live
Design Tools · 3D Apps · Articles · Downloads
View All Studios →📝 FE/PE Exam Prep Hub →📖 Engineering Glossary →
⚡ Popular Free Engineering Tools

Free Interactive Tools

Free online calculators, simulators, and design tools — no login required.

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Electronic Circuit SimulatorFree
Build & solve DC circuits online (nodal analysis)
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NEC Load CalculatorFree
NEC 220 service & feeder load calc
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Voltage Drop CalculatorFree
Conductor sizing per NEC 210.19
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Arc Flash CalculatorFree
IEEE 1584 incident energy & PPE
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HVAC Cooling LoadFree
Block load & tonnage (Manual J)
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Duct SizingFree
Equal-friction duct sizing
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Sprinkler HydraulicsFree
NFPA 13 density/area demand
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Fire Alarm Battery CalcFree
NFPA 72 secondary power sizing
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Structural Beam CalculatorFree
Reactions, shear & moment diagrams
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Commercial Electrical DesignerFree
Full NEC 220 commercial design + reports
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Radio / DAS DesignerFree
In-building DAS link budget & BDA sizing
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SCADA Architecture ExplorerFree
Interactive 3D Purdue-model SCADA system
Browse all tools →
📄 Technical Articles

Learn From Practicing Engineers

250+ free technical guides — NEC code, HVAC design, AI engineering, structural analysis, and more.

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NEC Electrical Code: A Practical Guide
How to read and apply NFPA 70 on real projects
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Fire Alarm System Design Fundamentals
NFPA 72 initiating devices, NACs, and annunciation
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HVAC System Design Basics
Air-side vs. hydronic systems, loads, and duct sizing
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How Large Language Models Work
Transformers, attention, tokenization, and inference
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Solar PV — How It Works
Panels, inverters, string sizing, and NEC Article 690
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Cybersecurity Fundamentals — CIA Triad
Confidentiality, integrity, availability, and NIST CSF
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Modbus RTU & TCP Protocol Guide
Register mapping, function codes, and industrial wiring
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PE Mechanical Exam — Complete Guide
Exam format, NCEES reference, and study strategy
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BACnet Building Automation Protocol
Objects, services, MS/TP vs IP, and BAS integration
Browse all 250+ articles →
📱 iOS Engineering Apps

95+ Professional
iOS Apps

From NEC electrical code tools and fire alarm exam prep to AI workflow builders and certification guides — every app is built for working professionals.

⚡ Electrical Engineering🔥 Fire Alarm🤖 AI & Automation📝 Exam Prep🏥 Health🎯 Lifestyle
Browse All 95+ Apps
Construction Drawings
Low Voltage Systems
Construction Drawings iPad
📱 App Preview

See It In Action

Real app screens — no mockups, no stock photos.

About EngineersUniverse

EngineersUniverse was created by a group of practicing engineers who wanted better reference tools in the field. Too many apps are generic. Too many books are outdated. We set out to build practical, professional-grade resources for real engineering work.

Today we publish Learning Studios and iOS apps covering electrical engineering, HVAC, fire alarm systems, SCADA, industrial automation, networking, and more — all built around real-world workflows and professional deliverables.

✉️ engineersuniverse26@gmail.com