Bicycle Gear Ratio & Speed Calculator See exactly how fast you will roll in every gear on your bike. Punch in your chainring and cassette teeth, pick a wheel size, and the calculator builds a colour-coded grid of speed, gear inches, development and ratio for every chainring × sprocket combination — useful when shopping for ...
Try the Tool »Camera Depth of Field (DoF) Calculator Plan sharp photographs with confidence. This calculator uses the exact thin-lens depth of field formulas to compute the hyperfocal distance, the near and far focus limits, and the total depth of field for any camera sensor, focal length, aperture, and subject distance. No guesswork, no approximations — just the ...
Try the Tool »Paper Size Reference & Converter Look up any standard paper size across the ISO, ANSI, and JIS systems and see its dimensions in millimeters, centimeters, inches, points, picas, and pixels at any common print or screen DPI. Switch to custom mode to enter your own width and height in mm, cm, inches, points, or pixels ...
Try the Tool »VO2 Max Estimator Calculator VO2 max is the maximum rate at which your body can take in and use oxygen during all-out exercise. It is the most widely used objective measure of aerobic (cardiorespiratory) fitness, and it scales with how hard, how long, and how often you can sustain endurance work. Reaching a true lab-grade ...
Try the Tool »Big Integer Calculator Compute exact results for math expressions that overflow ordinary calculators. The tool runs entirely on JavaScript BigInt, so factorial(1000), 25000, fibonacci(10000), and primality checks on trillion-digit candidates return every digit correctly — no scientific notation, no silent rounding. How to Use Type an integer expression, for example 2 ** 1000, factorial(100), or ...
Try the Tool »GPU VRAM Calculator Estimate how much GPU memory a transformer model needs for inference or training. Enter parameters, precision, batch size, and sequence length, and the calculator returns total VRAM along with a breakdown of weights, gradients, optimizer state, KV cache, and activations. It also compares the result against common GPUs (RTX 4090, A100, H100, ...
Try the Tool »Wire Size Calculator (AWG & mm²) Pick the right copper or aluminum conductor for any DC, single-phase AC, or 3-phase AC circuit. Enter your load current, supply voltage, and one-way cable length and the calculator iterates the NEC ampacity table to find the smallest wire that handles the load and keeps voltage drop under your ...
Try the Tool »Rule of 72 Calculator A fast, two-way doubling-time calculator. Enter an annual rate to see how many years money takes to double, or enter a target number of years to see the rate you need. The tool compares the classic mental-math shortcuts (Rule of 72, 70, and 69.3) against the exact compound result derived from ...
Try the Tool »Number Notation Converter Paste a number in any common notation and instantly see how it looks in every other one. Useful when you copy a figure out of a German invoice into a US spreadsheet, when an Indian accountant hands you a balance in lakhs, or when a paper expresses something in scientific notation that ...
Try the Tool »Musical Note Frequency Generator Convert any musical note to its exact frequency in hertz, MIDI note number, and wavelength — or go the other way and find the nearest note for any frequency you enter. An interactive piano keyboard lets you click any key to hear the tone through your browser, and you can switch ...
Try the Tool »Photography Exposure Value (EV) Calculator Dial in the exposure triangle without leaving the browser. Pick any two of aperture, shutter speed, and ISO and the calculator solves for the third, displays the resulting EV, and lays out every equivalent combination at the same exposure. A built-in scene reference based on the classic Sunny 16 rule ...
Try the Tool »Hardness Scale Converter Convert a single hardness measurement across the Mohs, Vickers (HV), Brinell (HB), and Rockwell A / B / C scales in one click. The converter uses ASTM E140 lookup data (with linear interpolation between rows) for the steel scales, plus a log-linear fit between Mohs and Vickers so you can compare metals ...
Try the Tool »Heat Index & Wind Chill Calculator Find out what the weather really feels like. This calculator combines temperature with humidity (for hot days) or wind speed (for cold days) to produce a “feels like” temperature using the official NOAA / National Weather Service formulas, then maps the result to a color-coded safety category so you ...
Try the Tool »Print & Typography Units Converter A live, bi-directional converter for the units designers, print professionals and front-end developers reach for every day: points, picas, pixels, millimetres, centimetres, inches, em and rem. Type into any unit and the rest update instantly using the DPI and font size you choose, so values match the actual medium you ...
Try the Tool »Multi-Base Arithmetic Calculator (Hex / Binary / Octal) Add, subtract, multiply, divide, and take the modulo of numbers written in binary, octal, decimal, or hexadecimal — and see the answer in all four bases at once. The calculator uses arbitrary-precision BigInt arithmetic, so large hexadecimal values stay exact, and it visualises the carry, borrow, shift-and-add, ...
Try the Tool »Musical Interval Converter Convert any musical interval between three universal units — semitones, cents, and frequency ratios — and instantly see the matching interval name (minor 3rd, tritone, perfect 5th, octave, and beyond). The tool is built for music theory students, instrument builders, audio engineers, and electronic-music producers who work with pitch in precise units ...
Try the Tool »Pet Food Portion Calculator Overfeeding is the single most common cause of preventable health problems in dogs and cats, but bag charts are notoriously rough — they cover the average couch-potato adult, not your pet. This calculator uses the same Resting Energy Requirement (RER) formula used by veterinarians and the WSAVA Global Nutrition Committee, then ...
Try the Tool »Decibel (dB) Level Converter The Decibel (dB) Level Converter turns a value entered in one decibel or linear unit into every related representation. Pick a reference type — Sound Pressure Level (SPL), Voltage, or Power — choose what your input is, and the tool computes the equivalent dB readings, the underlying linear quantity (pascals, volts, ...
Try the Tool »Irregular Polygon Area Calculator Type a list of vertex coordinates and instantly get the area, perimeter, and centroid of any flat polygon — convex or concave, axis-aligned or skewed, three vertices or thirty. The calculator uses the classic Shoelace formula so the answer is exact (no triangulation, no approximations), and it draws a live SVG ...
Try the Tool »Syllable Counter & Poetry Analyzer Paste any text, lyric, or poem and instantly see how many syllables each word and line contains. The tool also validates classic forms — haiku (5-7-5), tanka (5-7-5-7-7), and limerick (8-8-5-5-8) — and can highlight estimated stressed syllables so you can audit the meter of your verse. Unlike a chat-based ...
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Scoreboard is a fun way to keep track of your games, all data is stored in your browser. More features are coming soon!
Update: Our latest tool was added on Jun 18, 2026
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