JPNAS.NET / Tools

🧰 Tools

Small calculators I made for myself – for structural engineering, networks and computers, the mountains and a bit of math. They run completely in your browser: nothing is sent anywhere, and they work offline once the page is loaded.

🏗️ Structural engineering

📐 Beam CalculatorReactions, shear, moment and deflection of a simply supported beam or cantilever, with diagrams. 📏 Section PropertiesA, I, W, i and weight per metre for rectangles, tubes, box sections and I-beams. 🔩 Rebar CalculatorArea and weight of reinforcing bars, spacing per metre and bars for a required area. 🏛️ Euler BucklingCritical load, buckling length and slenderness of a column. 🌍 Earthquake SpectrumEurocode 8 response spectrum, natural period and base shear, with the Slovenian map values. ❄️ Snow Load – SloveniaGround and roof snow load by zone and altitude, SIST EN 1991-1-3. 📐 Slope ConverterPercent, degrees and 1:n – for roofs, ramps, drains and mountain paths.

💻 Networks and computers

🌐 IP Subnet CalculatorNetwork, broadcast, mask, usable range and hosts – and splitting into subnets. 💽 RAID / NAS CapacityUsable space and fault tolerance of RAID 0, 1, 5, 6, 10 and Synology SHR. ⏱️ Transfer & Backup TimeHow long a copy or backup takes – and Mbit/s versus MB/s. 🔑 Password GeneratorRandom passwords and passphrases, made only in your browser. 🐧 Chmod CalculatorLinux permissions: 755 ↔ rwxr-xr-x ↔ checkboxes. #️⃣ File Hash CheckerSHA-256 of a file in the browser, compared with the published checksum. 🧠 AI Memory CalculatorMemory for a local AI model and its context window – does it fit on your GPU?

⛰️ Mountains and climbing

🥾 Hiking TimeWalking time from distance, ascent and descent, with breaks and a map scale converter. 🌄 Sunrise & SunsetDaylight, civil twilight and golden hour for any place and date. 🌡️ Mountain WeatherTemperature at altitude, wind chill, air pressure and boiling point. 🧗 Climbing GradesFrench, UIAA and YDS, Font and V-scale, and the via ferrata scale. 🪢 Fall FactorFall factor and the estimated force on the climber and the top bolt.

🔁 Units

🔁 Engineering Unit ConverterkN, kgf, lbf, MPa, psi, kN/m, kNm, cm⁴, in⁴ and more.

🧮 Math

∫ Integral ExplorerWhat an integral really is: strips under a curve, multiplied and added up – step by step.

About these tools

Each tool shows the formulas and assumptions it uses, so you can check the result instead of trusting it blindly. They are for learning, planning and quick checks – the background is in my Digital Garden notes, and the commands I use every day are in the Cheat Sheets.