Every domain,
one index.
Engineering tools across 10 domains — free in your browser, each with a JSON API. Jump to a domain, or use a tool below.
Power, RF, analog and digital electronics — Ohm's law to junction-temp budgets.
IPC standards, trace width, impedance, via current, panelization yield.
ESP32, MQTT, LoRa, sensor & protocol calculators for embedded builders.
Convert firmware images between raw binary, Intel HEX, and Motorola S-record. Validates checksums, preserves sparse address maps, handles linear and segmented Intel HEX addressing, and emits a raw hex preview for inspection.
Project lifetime for an ESP32 (or any duty-cycled MCU) running on battery. Computes average current and lifetime from sleep current, wake current, wake duration, cycle period, and battery derating.
Encoders, regex, cron, schema converters and developer productivity utilities.
Free in-browser API testing tool (Postman alternative). Fire HTTP requests (GET, POST, PUT, DELETE, etc.) against any URL straight from your browser with custom headers and body.
Build a cron expression part-by-part, get a plain-English description, and preview the next five scheduled runs in your timezone. Handles ranges, lists, step values, and named days.
Convert raw git diff output to downloadable .patch files or compare code snippets to generate patches 100% client-side. Find common git diff commands.
Estimate monthly API cost for any LLM workload across Anthropic and OpenAI models. Includes prompt-cache and batch-API math so you see what you actually pay — not just the headline rate.
BIS standards, GST, civil and taxation tools — the long tail Indian engineers actually search for.
Compare Old vs New tax regime for FY 2025-26 (Finance Act 2025). Handles HRA, flexi bucket (food, NPS, LTA, mobile, uniform, prof-dev), 80C/80D/80CCD1B/24B, 87A rebate and surcharge tiers. Returns total tax, monthly TDS, effective rate, and a regime pick.
Compute the GST liability under the Reverse Charge Mechanism — the supplier doesn't collect tax, the recipient self-assesses it. Splits CGST/SGST or IGST, and flags Input Tax Credit eligibility.
Converters, formatters and calculators — the everyday stack every builder reaches for.
Calculate the exact number of days, weeks, months, or years between two dates, or add/subtract time from a date, with options to exclude weekends and holidays.
Compare the real ownership cost of an EV and a petrol vehicle using the numbers buyers already know: price, claimed range, mileage, local fuel rates, daily driving, currency and ownership period.
Generate a QR code from text, URL, or any payload. Pick foreground colour, background colour (or transparent), error correction level, margin and size. Returns SVG, base64 data URL, and ASCII preview.
Compare the long-term financial outcome of buying vs renting and investing the difference. Highly flexible, globally customizable with market presets.
mSLA, DLP and SLA workflows — exposure tuning, resin economics, FEP life and post-cure dosing for photopolymer printers.
Layer and bottom exposure plus Jacob's-curve cure depth from resin critical energy, penetration depth, printer LED power and layer height. Flags under-cure (delamination) and over-cure (brittle, blooming).
Estimate remaining FEP film life from accumulated print hours, average layer exposure, bottom-layer abuse and vat film type. Bottom exposures and high LED power age the film faster — both are factored in.
Per-print cost from resin used, bottle price, electricity and consumables — with a wastage uplift so failed prints don't surprise you. Returns total cost plus effective ₹ per ml and ₹ per gram.
Estimate how much resin a print will consume from the model volume, support overhead, raft and failure-buffer percentages — plus how much to pour into the vat including the FEP coverage minimum.
Estimate post-cure time in a wash-and-cure station from part thickness, resin type, UV intensity, wavelength match and rotation. Flags under-powered stations and over-cure brittleness.
Build, fly and survey — flight time, thrust-to-weight, LiPo headroom, FPV link budgets and photogrammetry mission planning.
Realistic flight-time estimate for any multirotor — uses hover efficiency (g/W), pack voltage, ESC efficiency, usable-capacity derating and a flight-style multiplier instead of the naive mAh ÷ current formula.
Compute thrust-to-weight ratio and hover throttle for any multirotor using the correct square-law throttle ↔ thrust relationship — not the linear approximation most calculators get wrong. Recommends a motor thrust to hit a target TWR.
Compute theoretical and practical line-of-sight range for any FPV video or control link using the Friis equation. Accounts for TX power, antenna gains, receiver sensitivity, system losses and fade margin, plus 60% Fresnel zone clearance for long-range planning.
Verifies whether a LiPo pack can actually sustain your drone's continuous and burst current draw. Computes voltage sag from per-cell internal resistance and warns when manufacturer C-ratings are overstated.
Compute ground sample distance, ground footprint, flight-line spacing, trigger interval and motion-blur speed limit for drone mapping missions. Add an area and battery flight time to get total image count, flight lines, mission duration, battery swaps and SD card size.
FDM, SLA, resin — slicing economics, exposure tuning, material trade-offs.
Mechanics, thermodynamics, fluids and materials math grounded in textbook physics.