Free Online Engineering Calculator

Open the Gear Calculator & Involute Gear SVG/DXF/STL

Calculate spur gear data (module, pitch diameter, tip and root diameter, centre distance, ratio, contact ratio) and generate true involute gears as SVG.

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Free to use
No signup
Nothing to install
Runs in your browser

Free to use

No signup

Gear Calculator & Involute Gear SVG/DXF/STL

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After

Open the Gear Calculator & Involute Gear SVG/DXF/STL

Illustration. Open the tool for the real thing.

Explained

What is the Gear Calculator & Involute Gear SVG/DXF/STL?

Enter a module, tooth counts for two gears, a pressure angle and optional profile shift and backlash, and this tool computes the full spur-gear data: pitch, base, tip and root diameters, addendum and dedendum, whole depth, tooth thickness, circular pitch, centre distance, gear ratio, contact ratio and output speed. It warns about undercut on small tooth counts and about a low contact ratio, the two classic design mistakes.

The same numbers drive a real involute gear generator. The tooth flank is calculated from the involute of the base circle, with proper root and tip arcs, and rotated into a complete gear outline. Download either gear — or the meshing pair at the correct centre distance — as an SVG or DXF (true millimetres, with a bore circle) for laser cutting and CNC, or as an STL solid with the face width you choose for 3D printing. A live preview shows the two gears meshed.

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Complete gear dataTrue involute profileSVG, DXF and STL

3 steps to your result

Open the tool and follow along. Nothing to install.

Enter module and the tooth counts of both gears.

Check ratio, centre distance and warnings.

Download SVG, DXF or STL of each gear or the pair.

What you get

Complete gear data

Diameters, depths, thickness, centre distance, ratio and contact ratio.

True involute profile

Flank from the base circle with tip and root arcs; profile shift and backlash supported.

SVG, DXF and STL

Laser/CNC outlines at 1:1 and a 3D-printable solid.

Meshing preview

See both gears in mesh at the right centre distance.

Free to use

AZRS tools are free to open and use.

Nothing to install

It opens in your browser, so there is nothing to download.

Used for

Pick one to see how it fits.

Use case

Mechanical engineering students

Check gear calculations and see the geometry.

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How it compares

A plain look at this tool next to the usual alternative.

	This engineering calculator	Desktop software
Install	Nothing to install	Usually an app or program to install
Account	No signup	Depends on the product
Cost	Free to use	Free or paid, depends on the product
Where it runs	In your browser tab	On your computer

Questions people ask

What is module?

Pitch diameter ÷ number of teeth, in millimetres — the standard measure of tooth size.

Is the profile a true involute?

Yes — computed from the base circle involute equation.

What about helical or bevel gears?

Only spur gears are generated.

Is the STL printable?

Yes — it is an extruded closed solid with a bore hole.

How do I use the Gear Calculator & Involute Gear SVG/DXF/STL?

1. Enter module and the tooth counts of both gears. 2. Adjust pressure angle, profile shift and backlash if needed. 3. Check ratio, centre distance and warnings. 4. Download SVG, DXF or STL of each gear or the pair.