Unit Converter, Every Unit at Once, Private and Offline

Length

How to type things shortcuts

The box understands more than plain numbers, and it will pick the unit for you when you name one:

A unit in the box, 12 psi, 350 F, 60 knots, 2.5 GiB, jumps to the right category and unit automatically.
Fractions, 3/8 or 1 1/2, the shop way of writing it.
Feet and inches, 5'11" or 5 ft 11 in, converted as one measurement.
Big or small numbers, 1,234,567 or 2.5e-6.
Click any result to copy that number to your clipboard.

Why show every unit at once? Most converters make you pick a "to" unit, which means you have to already know which unit you want, and you get one number per trip. This one converts into everything in the category the moment you type, so you can eyeball the whole scale and grab whatever you actually needed. Inches also come with the nearest 1/64 fraction, and lengths get a feet-and-inches reading, because that is how the tape measure is marked.

The ones that quietly bite people gotchas

A US gallon is not an Imperial gallon. The Imperial gallon is about 20% larger (4.546 L vs 3.785 L), which quietly wrecks recipes, fuel-burn math and anything copied from a UK, Canadian or Australian source. Both are listed here, labeled, side by side.
A gigabyte is not a gibibyte. Drive makers count GB as 1,000,000,000 bytes; Windows shows you GiB, which is 1,073,741,824. That is the entire reason your "2 TB" drive shows up as 1.82 TB. Both are in the Data list.
Megabits are not megabytes. Your 500 Mbps internet plan is about 62.5 MB/s at best, because there are 8 bits in a byte. Data rate is its own category here for exactly this reason.
MPG and L/100 km run backwards from each other. More MPG is better, more L/100 km is worse, and you cannot convert them with a multiply, it is a divide. Fuel economy is handled as its own special case, so the numbers come out right.
An ounce of weight is not an ounce of volume, and a troy ounce (precious metals) is heavier than a regular ounce. They live in different categories here, and the troy ounce is labeled.
Temperature has an offset, not just a scale. A 10 °F change is not 10 °F converted, which is why a "double the temperature" shortcut never works. Convert the actual reading.
Horsepower comes in two flavors. Mechanical (US, 745.7 W) and metric PS (735.5 W) differ by about 1.4%, enough to matter when comparing spec sheets across an ocean.
Pounds of torque are not pounds of force. Foot-pounds and inch-pounds differ by a factor of 12, and torque wrenches are sold in both. Mixing them up is how fasteners get stripped.