EngiToolbox
Engineering calculators that earn your trust
Hand-built by one engineer who cares — professional formulas, validated inputs, and clear outputs for workshop, desk, and classroom.
Beyond quick calcs
When a back-of-envelope isn't enough — CAM toolpaths, structural solvers, and seal design that ship with your Pro plan.
Browser-based CNC
Import geometry, generate 2.5D and 3D toolpaths, simulate cuts, and post G-code — without leaving the browser. Tool libraries and machine profiles sync to your account.
Structural FEA in 2D
Pick a truss, arch, cable-stayed or suspension style, sketch joints and members, then run a frame finite-element solver to find axial forces, bending moments, and the governing load factor.
Seal groove sizing
Size grooves against ISO 3601 and AS568 standards, check squeeze and stretch, and validate material compatibility — the kind of seal work that usually lives in a spreadsheet tab nobody trusts.
Free calculators stay free — Pro unlocks the solvers above plus PDF export and saved workspaces.
Designed and maintained by a single engineer — so every detail gets personal attention.
Every calculation is verified against engineering standards to ensure precision you can trust
Simple, modern design that provides a seamless experience for engineers and students alike
New calculators and refinements ship regularly, with every release shaped by real user feedback
EngiToolbox is built by one engineer obsessed with getting the details right. Use every core tool free — and if it saves you time, going Pro keeps the project independent and growing.
Get Started NowAll calculations are provided for reference only. Always verify results according to your specific engineering requirements.