Our Mission
CadnPDF was built to close the gap between engineering reference materials and the engineers who need them. Whether you are sizing a retaining wall footing, checking egress width for a code review, or downloading a detail drawing for a bid package, our goal is to have the resource you need — accurate, code-referenced, and immediately usable.
Who We Are
We are the CadnPDF Engineering Team: a group of structural, civil, and MEP engineering professionals with hands-on project experience across multiple disciplines. Our team has worked with ACI 318 reinforced concrete design, ASCE 7 wind and seismic analysis, IBC occupancy and egress, ASHRAE mechanical systems, NEC electrical service calculations, and IPC/UPC plumbing sizing.
Every calculator and drawing set published on this site is reviewed by at least one team member with relevant design experience in that discipline before it goes live. We do not publish unverified user-submitted content as technical guidance.
Why Our Calculators Are Trustworthy
Code-Referenced, Edition-Specific
Every calculator on CadnPDF cites the governing code or standard it follows — and the edition. You will see references to ACI 318-19, ASCE 7-22, IBC 2021, ASHRAE 62.1-2022, and similar. We list the edition, not just the title, so you know exactly which code cycle the formula comes from. When a code is updated to a new edition, we update the relevant calculators.
Derivations, Not Black Boxes
Our calculators show intermediate results so you can follow the calculation logic step by step. Formulas are derived directly from the code sections cited — the same mathematical approach used in professional engineering practice. You can trace every output back to an input and a code equation.
Conservative Defaults
Where a code allows a range of assumed values (such as a load factor, a friction coefficient, or an overstrength factor), our default inputs are set to conservative values. We document which defaults we use and why, so you can adjust them to match your specific project conditions.
CAD Drawing Quality
Our CAD drawing sets are reviewed for drafting standards, layer organization, and dimensional accuracy before publication. Drawings are provided in widely supported formats compatible with standard CAD and BIM workflows.
Important Disclaimer
The calculators, drawing sets, and technical references on CadnPDF are engineering reference tools — they are not a substitute for professional engineering judgment or a licensed engineer of record. All structural, mechanical, electrical, and plumbing designs for permitted construction must be designed by and bear the stamp of a licensed professional engineer registered in the jurisdiction where the project is located.
CadnPDF resources are intended to support and verify — not replace — that professional review. We do not provide engineering services, and use of our tools does not create a professional-client relationship.
Feedback and Corrections
Engineering accuracy matters. If you find an error in a calculator, a discrepancy with the code edition referenced, or a dimensional issue in a drawing, please let us know via our Contact page. We take correction requests seriously and review them promptly.