Convert between 12 categories — length, weight, temperature, volume, area, time, speed, data, pressure, energy, angle, and frequency. Batch convert to all units at once.
Converting 1 km to mi (length) works by routing both units through the meter base unit.
This tool runs 100% in your browser. All computation happens locally on your device — your input is never uploaded to any server. Results are for reference only.
Quick start: provide your numbers and the math happens on the spot — convert between metric and imperial units. Everything runs locally; nothing is uploaded.
FreeToolHub Unit Converter is a free browser-based tool — convert between metric and imperial units. No signup, no upload; everything runs locally in your browser.
Convert between metric and imperial units. Length, weight, temperature, volume, area, speed, data storage, and more. Free, instant, accurate.
The Unit Converter is a free calculator that translates values among eighty units across twelve categories: length, weight, temperature, volume, area, time, speed, data, pressure, energy, angle, and frequency. It covers the everyday Metric-Imperial pairs — meters to feet, kilograms to pounds, Celsius to Fahrenheit — as well as specialized units like knots, acres, psi, and petabytes. Temperature conversions apply proper offset formulas rather than simple multipliers, so Fahrenheit and Kelvin stay correct. A batch mode shows your value converted into every unit in a category at once, and results update instantly as you type. Everything runs locally in your browser with no signup and no ads.
Engineers and technicians use it for pressure (psi, bar, kPa), energy, and angle conversions when specs arrive in unfamiliar systems. Home cooks and bakers rely on it to rescue American recipes — cups, tablespoons, fluid ounces, and Fahrenheit ovens — when their kitchen scale thinks in grams. Students checking physics and chemistry homework convert length, volume, and temperature with proper offset handling. Travelers translate kilometers to miles, Celsius to Fahrenheit, and liters to gallons when renting cars abroad. Weightlifters meet their match when plates are labeled in pounds but the program is in kilograms. Even developers use it for binary data sizes, since kilobytes here correctly mean 1024 bytes.
(1) Pick a category from the grid of twelve buttons — length, weight, temperature, volume, area, time, speed, data, pressure, energy, angle, or frequency. (2) Enter your value, choose the From and To units from dropdowns that display each unit's full name and symbol, and use the Swap button to reverse direction instantly. (3) Read the result, which updates as you type; flip the 'Batch: convert to ALL units' switch to see your value expressed in every unit of that category at once — handy when you are not sure which unit you need. (4) Click '+ History' to store up to twenty conversions in your browser for quick reuse during a project.
Watch for the two classic conversion traps. First, gallons differ: a US gallon is 3.785 liters while an imperial gallon is 4.546, and this tool lists both so you can match the recipe or manual you are holding. Second, temperature is not a simple ratio — the converter applies the correct offsets, so 0°C is 32°F, not a naive multiple. For very large or small results, values are formatted with sensible precision rather than a wall of digits. If you convert repeatedly for one task, save entries to history so you can re-run them without retyping. And remember months are defined as 30 days and years as 365 in the time category.
One meter equals 3.28084 feet (exactly 1 ft = 0.3048 m by international agreement since 1959). The converter routes both units through the category's base unit, so the result matches NIST precision to full floating-point accuracy — and shows compound readings like 6 ft 2.8 in for height conversions.
Yes. Temperature is the one category where units are not simple ratios: Fahrenheit and Celsius have offset zeros. The tool applies the proper affine formulas (C x 9/5 + 32 for C-to-F) rather than multiplying by a factor, so 0 C converts to 32 F, not 0 F. Kelvin, Celsius, and Fahrenheit are all supported.
Twelve categories: length, weight, temperature, volume, area, time, speed, data storage, pressure, energy, angle, and frequency — roughly 90 units total. The Batch toggle converts your input to every unit in the category at once, which is handy for spec sheets and unit audits.
No. Recent conversions (up to 20) are saved only in your browser's localStorage so you can click one to reload it later. Nothing is transmitted anywhere, and clearing your browser data wipes the history instantly.
14 categories: length (meters, feet, miles), weight (kg, lbs, tons), temperature (Celsius, Fahrenheit, Kelvin), volume (liters, gallons, cups), area (hectares, acres), time, speed (mph, km/h, knots), data storage (bytes to TB), pressure, energy, power, angle, and frequency. All conversions use precise SI standard factors.
Yes. All factors use NIST (National Institute of Standards and Technology) definitions. The metric-to-imperial conversions use exact SI ratios (1 inch = 25.4 mm exactly). Temperature conversions use the standard formulas. Results display 8 significant digits, sufficient for engineering, cooking, and scientific applications.
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Why did the fish get bad grades?
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