SUUR case study · our own product · six weeks

Run fast. Math later.

PaceCalc is the product we built for ourselves — a running calculator PWA that puts every calculation a runner needs in one place. No login. No ads. Works offline.

The pace calculator on mobile, mid-calculation

Runners need five apps to plan one race

What pace for a 3:30 marathon? How does heat affect my time? What splits should I run for NYC? The answers live scattered across Strava, McMillan, V.O2, Runna, and random blog posts — each holding one piece of the math.

Nobody had put the whole toolkit in one place and made it fast, free, and honest: zero login, zero ads, and every formula shown with its sources.

So we built PaceCalc.

The full PaceCalc homepage, scrolling — The homepage — scroll and it browses itself

The pace calculator page, scrolling — The pace calculator — inputs, live result, methodology

Nineteen tools, one fitness score

Everything is connected by a shared VDOT fitness score. Calculate it once in the Race Predictor and every other tool picks it up automatically — interval paces, training zones, and 33 personalized workouts, all calibrated to your current fitness.

Pace Calculator, Triathlon, Run/Walk, Heat & Altitude, Age Grading, Weight Impact, Treadmill, Swim Pace, Boston Qualifier, and more — one platform instead of five apps.

19calculators at launch
33personalized workouts
15marathon courses, real elevation
66+pages prerendered at build

The build

Six weeks, zero backend

A PWA, not an app-store bet

React 18 with React Router 7, Vite, TypeScript, and shadcn/ui. Full PWA with Workbox caching — it works offline and installs like a native app, without waiting on a review queue. Deployed on Vercel with zero backend infrastructure.

66 pages before the first visitor

Every calculator, course, and article is prerendered to static HTML at build time — 66+ pages with structured data on each. 58 OG images generated via Satori, and 8 SEO articles driving organic traffic straight into the calculators.

A design system against slop

An explicitly anti-AI-slop system: monospace numbers with tabular alignment so pace data reads like a cockpit, left-aligned headers, functional motion only. No gradient clip-text, no purple accents. 189 tests hold the math to the same standard.

Banger Workouts — classic sessions tuned to your VDOT

Fifteen marathons, mile by mile

Real elevation data for courses like NYC and Boston. Grade-adjusted pace bands that account for every hill. Negative split strategies. Printable wristbands for race day.

Every course from New York to Tokyo, Berlin to Barcelona, with course highlights and mile-by-mile intelligence you can carry on your wrist.

The NYC Marathon course page, scrolling — TCS New York City Marathon — the course, charted

Race Predictor — PaceCalc — **Race Predictor** one result in, every distance projected — plus the VDOT score

Live results — PaceCalc — **Live results** no submit button — the answer updates on every keystroke

Course elevation — PaceCalc — **Course elevation** real gain and loss data, charted mile by mile

Built like a client project. Shipped like a product.

19 calculators at launch
15 race courses, real elevation
66+ prerendered pages
6 weeks, zero to live

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