I'm a Structural Engineer, and I Built a Free Calculator Because Existing Tools Cost $10K+

Orion Woo — Tue, 11 Aug 2026 17:08:35 +0000

Three years ago I sat in a project meeting with a contractor who asked: "Can we use FRP grating instead of steel on this cooling tower platform?"

I said yes.

Then I spent the next three hours doing hand calculations for a single beam. Timoshenko shear deformation. Environmental knockdown factors. Orthotropic stiffness matrices. ASCE/SEI 74-23 load combinations.

Three hours. One beam.

I stared at my spreadsheet and thought: this is why nobody uses FRP.

The Tooling Gap That Nobody Talks About
If you're a structural engineer working in steel or concrete, your workflow is straightforward. You open RISA or STAAD or RAM. You model. You get results. You print a report. Done.

If you want to design in FRP?

Your options are:

Option Cost Problem
Proprietary FRP design software $8,000–$15,000/year Nobody's paying that for a maybe-material
Spreadsheet hand calcs Free (in $) but 3 hours per beam (in sanity) Error-prone, not reviewable
Ask the manufacturer Free They'll send you a PDF with cherry-picked data
Give up and spec steel — The safe choice
That last option is what most engineers pick. And that's the real barrier to FRP adoption: not the material properties, not the cost, not the code — the tooling gap.

What I Built
A few months ago I finally decided to fix this. I built a free, browser-based FRP profile calculator that handles the annoying stuff engineers hate doing by hand:

LRFD load combinations per ASCE/SEI 74-23
Environmental knockdown factors — outdoor exposure, chemical environment, UV
Timoshenko shear deformation correction (because FRP deflects more than Euler-Bernoulli predicts)
Steel-to-FRP section equivalence — input your steel I-beam and it finds the FRP alternative
A searchable database of 65+ real pultruded sections from multiple manufacturers
The idea is simple: you should be able to get a preliminary FRP design in 5 minutes instead of 3 hours.

The Tech Stack (Because This Is Dev.to)
Nothing fancy. I wanted zero friction for users — no signup, no download, no email gate.

Frontend: Vanilla JS + Tailwind CSS. No framework overhead because the main compute is all client-side math, not DOM manipulation
Calculations: Pure JavaScript. All the beam theory, load combinations, and section property lookups run in the browser. No server round-trips
Section database: Static JSON. 65+ real manufacturer profiles with A, Ix, Iy, Sx, Sy, J, weight-per-foot. Pre-computed where possible to avoid runtime number crunching
Hosting: Static site. Cheap, fast, no backend to maintain
The hardest part wasn't the code — it was translating ASCE/SEI 74-23 into algorithmic logic. The standard has edge cases: different phi factors for different failure modes (flexure vs. shear vs. compression), different environmental knockdowns depending on whether the section is exposed to chemicals or just weather, and interaction equations for combined loading.

I probably spent 40% of the time on the math, 30% on testing edge cases, 20% on UX (making sure a structural engineer who's never seen the tool can figure it out in 30 seconds), and 10% on actual frontend code.

What I'd Do Differently
Unit handling: FRP design mixes imperial and metric constantly (ksi for stress, inches for deflection, lbs/ft for weight). I should have built a unit conversion layer from day one instead of retrofitting it
Mobile UX: Engineers in the field use phones. My first version was desktop-only. Fixed now, but I lost early mobile users
PDF export: Engineers want reports. A "Print to PDF" button with formatted output would be more useful than I initially thought

More manufacturer data: I started with one manufacturer's section tables. Users immediately asked for others. Building a normalized schema for cross-manufacturer comparison was more work than I expected

The Real Lesson
If you work in a niche industry (construction, manufacturing, agriculture, any "non-tech" field), here's what I learned:

The software tooling in specialized industries is terrible. Not because the problems are hard — the math isn't harder than what you see in web dev. It's terrible because the market is small, so existing vendors charge enterprise prices and no startup wants to compete.

That's an opportunity.

My FRP calculator gets about 90 organic searches per month for "frp profile calculator" and related terms. That's tiny by SaaS standards. But every single user is a practicing structural engineer who might specify FRP on a real project. The conversion from "used the tool" to "requested a quote" is absurdly high compared to any other marketing channel.

If you can build a genuinely useful free tool for a niche professional audience, the SEO and word-of-mouth you get will outperform any content marketing strategy. Engineers share useful tools. Contractors share useful tools. You don't need to go viral — you need to be the tool that gets forwarded in a project email.

Try It / Break It
The calculator is free at f1composite.com/frp-profile-calculator. No signup, no email, no catch.

If you're a structural engineer who's used FRP — or tried to — I'd love feedback. What would make this actually useful in your workflow?

I build free engineering tools at F1 Composite. Previously: structural engineer who got tired of spreadsheets.

DEV Community: Orion Woo

I'm a Structural Engineer, and I Built a Free Calculator Because Existing Tools Cost $10K+

More manufacturer data: I started with one manufacturer's section tables. Users immediately asked for others. Building a normalized schema for cross-manufacturer comparison was more work than I expected