RedBison Now Covers 400+ Tools, From File Converters to Engineering Calculators

Over 180 new tools: browser-based file and media converters, everyday calculators, and 77 engineering calculators across civil, mechanical, electrical, electronics, fluids and more, each with a guide.

2026-10-28 · 7 min read

RedBison started as a set of developer utilities: a JSON formatter, a regex tester, hash and UUID generators. Over the last weeks the catalog has grown past 400 tools, and most of the new ones are for people who do not write code for a living. There are file and media converters that run in your browser, everyday calculators for money, health and maths, and a new group of 77 engineering and design calculators for civil, mechanical, electrical and electronics work, thermal and fluid problems, HVAC, carpentry, sheet metal and automotive jobs. Every one of them is free, has no ads, needs no account, and comes with a guide that explains the method behind the number.

This post explains what was added, how we checked that the answers are right, what runs locally and what does not, and how AI assistants can find and use the tools.

Engineering calculators, one field at a time

The new Engineering Calculators category is organised the way the trades and disciplines are. Each subcategory groups the sums that come up together on a real job.

• Civil and structural (11). The Beam Deflection Calculator covers simply supported, cantilever and fixed beams and checks the result against span-over-360 style limits. The Shear and Bending Moment Calculator draws the diagrams for point loads, distributed loads and overhangs. Section properties, Euler and AISC column buckling, steel weights, rebar take-offs, concrete mix ratios, brick and block counts, asphalt tonnage, cut and fill volumes and the distance between two GPS coordinates complete the group.
• Mechanical (10). Torque and power, gear trains, pulleys and belt length, bolt tightening torque and preload, compression springs, axial stress and strain, bearing L10 life, hydraulic cylinders, tap drill sizes and machining speeds and feeds.
• Electrical (7). The Wire Size Calculator picks a conductor from the NEC ampacity table with derating and then checks voltage drop. Single and three-phase power, power factor correction, transformer sizing, battery runtime, solar arrays and generator sizing sit alongside it.
• Electronics (10). LED resistors, voltage dividers, series and parallel parts, capacitor codes, RC filters, 555 timers, RLC impedance, op-amp gain, decibels, and a PCB Trace Width Calculator based on the IPC-2221 equations.
• Thermal, fluids and HVAC (16). Heat loss and U-values, thermal expansion, specific heat, heat exchanger LMTD, water heating time, flow rate, Reynolds number, pipe pressure drop with the Colebrook equation, pump power, Bernoulli, hydrostatic pressure, tank volumes, orifice flow, duct sizing, air changes per hour and water pipe sizing.
• Carpentry (7). Board feet, rafter lengths and cuts, wall framing, decks, drywall, crown molding miter and bevel angles, and baluster spacing, all with feet-and-inches input that understands fractions such as 5' 3-1/2".
• Sheet metal and welding (7). Bend allowance with the K-factor, sheet weight, gauge to thickness by material, cone flat patterns, press brake tonnage, punching force and fillet weld size.
• Automotive (4). Engine displacement, static and dynamic compression ratio, horsepower from torque or quarter-mile results, and road speed in each gear.

Five design calculators sit under Creative and Design: a PX to REM converter, a PPI calculator, a print size calculator, a golden ratio calculator and a modular type scale generator.

Everyday calculators and converters

Alongside the engineering tools, 94 everyday calculators now cover mortgages and loans with full amortization schedules, savings, inflation, retirement accounts, salary and overtime, sales tax and VAT, business pricing and depreciation, body fat, running pace and heart rate zones, due dates and ovulation, and a full set of maths calculators for percentages, fractions, triangles, statistics and more. Construction and home tools estimate concrete, tile, roofing and stairs.

The converters handle files people usually upload to a stranger's server. The Video Converter runs ffmpeg compiled to WebAssembly, PDF to Word rebuilds editable text from a PDF, Image to Text reads screenshots and scanned pages with OCR, and the Archive Converter creates and extracts ZIP, 7Z, TAR and other formats. Spreadsheets, Word documents, EPUB ebooks and HEIC photos are covered too.

How we checked the answers

A calculator that gives a confident wrong number is worse than none, so accuracy got more time than layout. The calculation code for every new tool is kept separate from the page and has its own automated tests, and those tests compare results with values published by someone else rather than with our own earlier output. A few examples:

• Beam deflection is checked against the standard 5wL⁴/384EI result for a uniformly loaded simple span and the AISC beam tables.
• Steel weights, rebar masses and pipe weights are checked against EN 10210 and EN 10219 section tables, ASTM A615 and ASME B36.10.
• The trace width calculator reproduces the published IPC-2221 widths for a 2 A trace, about 31 mil outside and 80 mil inside.
• Bolt torque uses ISO 898-1 and SAE J429 proof loads, and the spring calculator reproduces worked problems from Shigley's Mechanical Engineering Design.
• Wire sizing follows NEC Table 310.16 and states which edition it uses.
• The coordinate distance tool matches the Geoscience Australia Vincenty test line to the millimetre.

Where we could not confirm a value against a primary source, the page says so and labels the number as typical, and every value of that kind is editable. Engineering results also carry a short note: they are for checking, learning and preliminary design, and anything that carries load, current, pressure or people still needs a qualified engineer or licensed tradesperson working to the code that governs the job.

Each calculator was also loaded in a real browser on a desktop and a phone-sized screen and given known inputs to make sure the page shows what the tests promise.

A guide for every engineering calculator

Each of the 77 engineering and design calculators has its own article, and each article tries to answer the questions a colleague would ask. Where does the formula come from? What units and sign conventions does it assume? What do the codes and handbooks say about limits? What does a worked example look like? When does the simple model stop being good enough? The guides on sizing electrical wire, beam deflection formulas, PCB trace width and Darcy-Weisbach friction loss are good places to start.

What runs on your device

Almost everything runs in your browser tab. Numbers you type into a calculator are never sent to a server, and files you drop into a converter are read and written on your own machine. There are a few honest exceptions. The video and audio tools download the ffmpeg engine, about 32 MB, from a public CDN the first time you use them, and the OCR tool downloads its engine and language data the same way. Your files still stay local. The Currency Converter fetches European Central Bank reference rates, and only the currency codes are sent. Each of those pages says so near the top.

Available to AI assistants

The full catalog is published for AI assistants and crawlers. The AI access page explains how to connect ChatGPT, Claude, Cursor and other clients to the RedBison MCP server. Its discovery tools, search_tools, get_tool and list_categories, cover all 400+ tools, including the new converters and calculators, so an assistant asked for a voltage drop or a bend allowance calculator can find the right page and its guide. More than 50 tools can also be run directly over MCP. The same catalog is available as llms.txt, llms-full.txt and a machine-readable ai-tools.json manifest.

Tell us what is missing

The engineering set reflects the calculations we hear about most, not every one that exists. If your field needs a tool that is not here, or a result disagrees with a handbook you trust, tell us through the feedback link on any page and include the source you are comparing with. You can browse the full list from the Engineering Calculators and Calculators pages, or see every tool on one page in All Tools.

Browse all tools