About EngiToolbox
Engineering calculators built for real work
EngiToolbox is built and maintained by a single practising engineer — 23+ precise tools for structural, mechanical, and electrical work, kept free at the core because good engineering tools should be within everyone's reach.
32+
Tools & calculators
Free
Core tools, no paywall
SSO
Google & email sign-in
Web
Desktop & mobile ready
Our mission
EngiToolbox started on a workbench, not in a boardroom. It is designed, coded, and maintained by one qualified engineer with a deep love of manufacturing and the craft of getting the numbers right — built to give engineers, students, and technicians a reliable, genuinely pleasant place to run everyday calculations. Free at the core, polished in every detail.
What we offer
Discipline-organised calculators with validated inputs and clear outputs. Every link below is a live tool on EngiToolbox.
Why choose EngiToolbox?
Engineering-grade accuracy
Industry-standard formulas with input validation and tested reference cases so you can trust the numbers on real projects.
Intuitive, fast interface
Clear inputs, immediate results, and diagrams where they matter — designed for desk, classroom, and shop-floor workflows.
Comprehensive reference
Material properties, unit conversion, and discipline-specific helpers in one place instead of scattered spreadsheets.
Free core access
Every calculator stays usable for free, with worked-example previews on our Pro solvers. Upgrade to Pro or Team for ad-free browsing when you need exports, unlimited saves, advanced modes, or the API.
Your free account
Sign in with Google or an email magic link to unlock saves, PDF exports, and API keys. Calculators stay free — an account adds workflow features when you need them.
- Save and revisit calculations
- Ad-free browsing (Pro & Team)
- Export branded PDF reports (Pro)
- Manage API keys (Pro)
- Sync across devices via Google or email
One engineer, every tool
Every calculator here is built, tested, and looked after by the same person — a qualified engineer who came up through manufacturing and still sweats the details. That is why the formulas are checked against real reference cases, the interface stays clean, and your feedback turns into improvements fast. Upgrading to Pro is what keeps this independent project sharp and growing.
Accuracy
Correct formulas and tested edge cases first.
Accessibility
Free core tools for every engineer, everywhere.
Clarity
Inputs and outputs you can explain to a colleague.
Improvement
New calculators and refinements every month.
Spotted a glitch?
After months of building and polishing one feature after another, the odd rough edge slips through — I'm one person, and I'm only human. If something looks off, miscalculates, or just feels clunky, please tell me what happened and I'll fix it. Every report genuinely helps make these tools better for the next engineer.
Frequently asked questions
What is EngiToolbox?+
EngiToolbox is a free online engineering calculator platform with 23+ tools for structural analysis, mechanics, materials, machining, and electronics. It is built for engineers, students, and technicians who need fast, accurate results without spreadsheet setup.
Is EngiToolbox free to use?+
Yes. All core calculators are free with no sign-in required. Optional Pro and Team plans remove on-site advertising and add saved calculations, branded PDF exports, advanced modes, and API access — and they directly fund the upkeep of this independent, one-person project.
How do I sign in to EngiToolbox?+
Create a free account at /auth/signin using Google sign-in or an email magic link. Signing in lets you save calculations, export PDF reports, and manage API keys from your dashboard.
What engineering calculators are included?+
EngiToolbox includes unit conversion, stress and beam analysis, moment of inertia, hoop stress, friction, SUVAT kinematics, resonance, damping, centrifugal force, materials lookup, thermal expansion, speeds and feeds, drill depth, O-rings, limits and fits, PCD, and electronics tools such as voltage dividers and RC networks.
How accurate are EngiToolbox calculations?+
Calculators use standard engineering formulas and are tested against known reference cases. Results are for design reference — always verify against your project codes, standards, and safety requirements.
What is the difference between Free and Pro?+
Free keeps every calculator usable, with up to 3 saved calculations, worked-example previews on the premium solvers, and ad-supported browsing. Pro and Team remove on-site advertising and add branded PDF report exports, unlimited saved calculations, advanced calculator modes, live access to the premium solvers, and monthly API access. Upgrading is also the simplest way to support an independent project built by one engineer. See /pricing for current plans.
Can I use EngiToolbox on mobile?+
Yes. The interface is responsive and works on phones, tablets, and desktops so you can run calculations in the workshop or on site.
Who built EngiToolbox?+
EngiToolbox is designed, built, and maintained by a single qualified engineer with a background and genuine passion for manufacturing. Every calculator is hand-built and tested by the same person, with accuracy, clarity, and a genuinely good user experience as the priorities. Pro subscriptions are what keep the project independent and improving.
Ready to streamline your workflow?
Start with any free calculator, or sign in to save work and export reports.
Machine-readable site summary for AI assistants and crawlers.
All calculations are for reference only. Always verify results against your project codes, standards, and safety requirements.