Frequently asked questions

All 106 calculators are free to use, without an account and without a time limit. 103 of them produce a verification PDF, and for 17 that PDF is free as well. For the others you pay for the export: the verification PDF and export files such as the cam contour for CAD import (Cam design calculator). See pricing →

The single purchase is a one-off payment with no subscription: it unlocks exactly one calculator, with unlimited exports, and it does not buy a single document. For that calculator we guarantee at least 36 months of operation from the date of purchase; after that it keeps running for as long as we operate the website. The annual subscription unlocks every calculator for as long as it runs. If you work with one particular calculator regularly, buy it once; if you keep switching between calculators, the subscription is the better fit.

The calculators with the scope of specialist software, for example Cam design, Spur gear geometry, and MSA carry a higher one-off price. Each of them replaces a whole package of work rather than a single formula - work that would otherwise call for specialist software or a day by hand. The annual subscription includes them at no extra charge. Which calculator carries which price is stated on the pricing page and at the calculator itself. See pricing →

These calculators output files of their own, and different ones at that: Cam design: cam contour as XYZ points (SolidWorks, Excel, CSV); Spur gear geometry: tooth contour of both gears (DXF, Excel, CSV); Kinematics Studio: mechanism drawing (DXF) and value table over the cycle (Excel, CSV). All of them without watermark and without copy protection, the DXF in version R2000. What the DXF holds depends on the calculator - for the spur gear the tooth contour, for the linkage studio the whole drawing of the mechanism on separate layers. Every other calculator delivers the verification PDF. A higher price therefore does not mean there are export files: the price and the kind of output are two different things.

Yes. Payment is handled by Paddle as merchant of record, and Paddle issues the invoice with VAT shown separately. Businesses can enter their VAT identification number during checkout.

Any time, with no notice period, via the cancellation button on this website or directly at Paddle; you will also find the link in every payment confirmation. The subscription runs for one year and cancellation takes effect at the end of that paid year: until then the export stays unlocked, after that nothing further is charged.

For every calculator bought outright, at least 36 months of operation from the date of purchase are guaranteed, including the updates required to keep it contractually sound. We announce a discontinuation at least twelve months in advance in text form. From that announcement onwards no subscriptions are entered into or renewed, so every running subscription period is still performed in full. If the guaranteed operating period of a one-off purchase is still running at the shutdown date, we refund the share of the purchase price attributable to the remaining time. The reports and export files you already created are yours anyway and work independently of the website. See the terms of use →

Yes. The generated PDF and the export files are yours: you may hand them to clients and manufacturers, file them in project records and include them in quotations or documentation.

All inputs, the results, the formulas used with their source, and the charts of the calculation. Plus fields for project, part and engineer, so the document fits into a file without rework.

Not for calculating. For the 17 calculators with a free report you do not need one for the PDF either. After a one-off purchase the export runs on the token from your purchase confirmation, again without an account. You need an account to save calculations and for the subscription.

You receive a sign-in link by email instead, valid for 60 minutes. That saves you another password, and a password that does not exist cannot be stolen.

Calculations run in your browser, on your device. Your inputs are only transmitted when you save a project or generate a document. Privacy policy →

Yes, at any time and without asking: in your account, using the delete button. This removes the account, the saved projects and the sign-in data. Purchased unlocks expire with the deletion and cannot be restored, including the tokens from your purchase confirmation. A running subscription is not cancelled by this; cancel it with our payment partner Paddle.