Technical Calculator Suite

The client needed a suite of specialized engineering calculators for their professional user base. These weren't simple converters — they involved complex mathematical models with interdependent variables, industry-standard formulas, and edge cases that general-purpose tools couldn't handle.

Key requirements:

• Mathematical accuracy — Results had to be correct to industry standards. Errors in engineering calculations have real-world consequences.
• Instant feedback — Users needed to see results change as they adjusted inputs. No loading spinners, no submit buttons.
• Mobile-friendly — Engineers use these tools on-site, often on phones and tablets.
• Clear data visualization — Raw numbers aren't enough. Users needed charts, diagrams, and visual indicators to interpret results.
• Exportable results — PDF reports and shareable links for documenting calculations in project files.

We built the suite as a React application with all computation running client-side in TypeScript — no server round-trips, no latency, no dependency on network for calculation accuracy.

• TypeScript computation engine — Every formula implemented with strict typing and comprehensive unit tests. Edge cases (division by zero, out-of-range values, interdependent limits) handled gracefully.
• Real-time reactive UI — Inputs and outputs connected through reactive state. Adjusting any value instantly recalculates all dependent fields and charts.
• Responsive design — Full functionality on mobile. Input fields designed for thumb-friendly interaction. Charts resize and adapt to screen width.
• Validation with guidance — Not just "invalid input" — clear messages explaining acceptable ranges and why, based on engineering standards.
• Shareable state via URL — Calculation parameters encoded in the URL. Users can share a specific calculation by copying the link.

The calculator suite launched to immediate adoption:

• 1,000+ monthly active users within three months of launch, growing through word-of-mouth and search.
• Sub-millisecond computation — even the most complex calculations with multiple interdependent variables return instantly.
• Zero reported calculation errors — comprehensive testing and validation ensure industry-standard accuracy.
• Perfect mobile scores — 100/100 Lighthouse performance on mobile, critical for on-site usage.

The tools became the client's primary traffic driver, attracting engineering professionals who then discovered their core services.