Miles to Thou (mi to thou)

1 mile equals 63,360,000 thou exactly.

1 mile = 63,360,000 thou

How to convert miles to thou

To convert miles to thou, multiply the number of miles by 63,360,000. This factor is exact. To go the other way, multiply thou by 1.578282828×10⁻⁸ (rounded).

thou = miles × 63,360,000

Example: 10 miles = 633,600,000 thou.

About these units

Mile (mi)

US & ImperialCurrent unit

5,280 feet or 1,760 yards, exactly 1,609.344 meters. This is the statute (international) mile used on US and UK roads.

A thousand paces gave the mile its name. It descends from the Latin mille passus, the Roman mile, by way of Old English mil and Middle English myle. For centuries after Rome, miles of many lengths coexisted; a sixteenth-century Mercator map, for example, shows small, medium and large Flemish miles on a single scale bar. The English statute mile was fixed by an Act of Parliament under Elizabeth I in 1593, which declared that a mile contains eight furlongs, or 5,280 feet.

The 1959 international yard and pound agreement made that mile exactly 1,609.344 meters. A slightly longer US survey mile, about 1,609.347 meters, lingered in American land surveys and was slated for retirement from 1 January 2023. Today the mile is the road unit of the United Kingdom, the United States, Liberia and Myanmar, along with several territories such as the Bahamas, Belize, Guam and the US Virgin Islands. In Canada it survives chiefly in rail transport and horse racing.

1 mile = 1,609.344 meters (exactly).

Sources: Wikipedia: Mile; Wikipedia: Foot (unit); NIST Guide to the SI, Appendix B.8: conversion factors

Thou (thou)

US & ImperialCurrent unit

One thousandth of an inch (0.0254 mm), also called a mil. Used in machining, plastics and the thickness of films and wire.

Machinists say a part is out by a few thou, and the word is a clipping of thousandth, keeping only the first syllable. In North America the same length is often called a mil, which is easy to confuse with a millimetre in international drawings. One thou is a thousandth of an inch, which is exactly 0.0254 mm or 25.4 micrometres, so about 39 of them fit in a millimetre. The word is both singular and plural.

Joseph Whitworth pressed in 1857 for engineers to think in decimal thousandths instead of fractions of an inch, a habit that needed vernier calipers and micrometers to put into practice. Today the unit describes the thickness of paper, foil, wire, plastic sheet and paint films, with a plastic ID card about 30 thou thick. It also appears in older spark-plug gaps, gasket thicknesses and circuit-board geometry. For finer work, a tenth, meaning 0.0001 inch or 2.54 micrometres, is common, and gauge blocks are often given in millionths or in micrometres.

1 thou = 0.0000254 meters (exactly).

Sources: Wikipedia: Thou (unit); Wiktionary: thou

Related conversions

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