All-in-One Online Unit Converter

This unit converter is designed to be fast, readable, and dependable on any screen size. It covers nine everyday categories that people actually use: length, mass, temperature, speed, area, volume, data storage, time, and pressure. Pick your category, choose a source unit and a target unit, type a number, and press Convert. The interface stays minimal by default, yet it still exposes the essentials few tools bother to show, like a clear formula line and an easy copy button for sharing results in chat or email.

Accuracy matters. Each category uses stable, widely accepted constants. A meter is always 1 m, an inch resolves to 0.0254 m, and a statute mile resolves to 1609.344 m. Conversions that involve offsets as well as scale—like Celsius to Fahrenheit—are routed through Kelvin so that both slope and intercept are applied correctly. The Decimals control only affects display; calculations keep full precision until the final round step. That means you can bump decimals up when you care about small differences, or keep them low to avoid visual clutter when the magnitude is large.

The workflow is simple but thoughtful. Categories prefill the most common pairs so you can convert centimeters to inches, kilograms to pounds, liters to gallons, and kilometers per hour to miles per hour without hunting through menus. When you change category, the unit lists repopulate with sensible defaults, and the page remembers your last selection locally so frequent tasks feel familiar the next time you visit.

The result block is intentionally clean. The main line shows exactly what you typed, the interpreted unit labels, and the converted value. Beneath that, the formula line explains how the number was derived in plain language. If you are working with a colleague or documenting a calculation, you can copy the headline with a single click. The converter also respects reduced-motion preferences and uses a subtle flash animation to draw focus to new results without jarring motion.

A few practical tips help avoid common pitfalls. For very small or very large quantities, use scientific notation in the input field; the converter accepts values like 3e-6 and 2.5e8. If you need to keep track of significant figures, set the Decimals control to a limit that matches your source measurement rather than your target unit; this avoids implying more precision than your instruments provide. When converting temperatures, remember that differences and absolute values are not the same thing; a temperature change of 10 °C maps to a 18 °F change even though a specific temperature of 10 °C converts to 50 °F.

Everything runs locally for speed and privacy. The page does its math in your browser without sending your values to a server. That makes it quick on mobile connections and suitable for calculations you would rather keep on your device. If you step away and come back later, the converter restores your last category, unit pair, and decimals so you can pick up where you left off.

Use cases are broad and practical. Home cooks convert grams to ounces or milliliters to cups. Travelers toggle kilometers to miles and Celsius to Fahrenheit. Students check square meters against square feet when sketching a room layout. Engineers sanity-check pressure readings in kilopascals against psi. Content creators convert data sizes and bit rates without opening a spreadsheet. The goal is the same everywhere: a clear, trustworthy answer in as few steps as possible.

Limits keep the experience predictable. The tool focuses on deterministic conversions with fixed relationships. It does not estimate things that depend on context, like fuel economy under different driving conditions or cooking substitutions across ingredients. By keeping scope tight, the interface remains quick and the math remains transparent.

Which categories are supported?

Length, mass or weight, temperature, speed, area, volume, data storage, time, and pressure. Each category contains the most common units first so typical pairs are easy to reach.

How does rounding work?

Use the Decimals control to choose 0–8 places. The converter rounds only the displayed result; internal math carries precision until the final step to avoid compounding error.

Does it work offline?

Yes. After first load, everything runs locally in your browser. If storage is available, your last settings are remembered so repeat conversions are even faster.