The calculator is free.
Pay when you issue a report.
Everything that involves calculation, sharing links, and reviewing results is free — forever. Issuing watermark-free engineering deliverables costs $9 for 3 days, then $49 every 4 weeks. Cancel anytime.
The calculator, every check, the on-screen report, and shareable links. Built for iteration.
- Full calculator — all methodologies (Mechanics, BTH-1, EC3, DNV)
- Live schematic, governing check, assumptions, warnings
- Full on-screen report with PREVIEW watermark
- Shareable configuration links
Watermark-free PDFs for all reports while your access is active. Then $49 / 4 weeks.
- Watermark-free reports, ready to print or save as PDF
- Unlimited reports while subscribed
- Engineer profile + stamp on every report
- Cancel anytime via the Stripe Billing Portal
Then $49 / 4 weeks. Cancel anytime from your account. Or open the calculator and unlock from a report.
A deliverable, not a calculation.
The calculation engine is free because the value is in the deliverable: a traceable, watermark-free document you can hand to a reviewer or a client. We don't meter calculation, don't sell your data, and don't bury the scope disclaimers. Paying removes the preview watermark — it does not make this a substitute for FEA or detailed engineering review.
Start at $9, then $49 / 4 weeks.
Your first payment is $9 for 3 days of full access. After that, your subscription automatically renews at $49 every 4 weeks until you cancel. Manage billing, update your card, or cancel anytime from the Stripe Billing Portal on your Account page.