Convert Thou to Miles
1 thou is 1.58e-8 mi. One thou is exactly 1.57828282828e-8 miles.
One thou is 1.5783 × 10^-8 miles. To convert thou to miles, multiply by 1.5783 × 10^-8; to go the other way, divide by 1.5783 × 10^-8 or multiply by 63360000. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST.
Factor checked against the defining standard · How we check
- Thou × 1.5783 × 10^-8
1 * 1.5782828e-80 mi
1 thou in every length unit
| Unit | Value | Exact factor |
|---|---|---|
| inches | 0.001 in | × 0.001 |
| feet | 0.00008333333333 ft | × 0.0000833333333333 |
| yards | 0.00002777777778 yd | × 0.0000277777777778 |
| miles | 0.00000001578282828 mi | × 0.0000000157828282828 |
| millimeters | 0.0254 mm | × 0.0254 |
| decimetres | 0.000254 dm | × 0.000254 |
| centimeters | 0.00254 cm | × 0.00254 |
| meters | 0.0000254 m | × 0.0000254 |
| kilometers | 0.0000000254 km | × 0.0000000254 |
| nautical miles | 0.00000001371490281 nmi | × 0.0000000137149028078 |
| micrometers | 25.4 µm | × 25.4 |
| nanometers | 25,400 nm | × 25,400 |
| thou (as entered) | 1 thou | — |
Factors are entered by hand from NIST rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert thou to miles? The converter and the working
- 1.Take the measurement in thou.
- 2.Multiply by 1.5783 × 10^-8 — that is how many miles fit in one thou.
- 3.To go back the other way, divide by 1.5783 × 10^-8, or multiply by 63360000.
Worked example: 25 thou to miles
- Formula
- thou × 1.5783 × 10^-8 = mi
- Arithmetic
- 25 × 1.5783 × 10^-8 = 3.95e-7 mi
- Answer
- 25 thou = 3.95e-7 mi
The factor is rounded for display; the figure above is computed from the full value.
Thou to miles conversion table
| Thou | Miles |
|---|---|
| 1 thou | 1.58e-8 mi |
| 2 thou | 3.16e-8 mi |
| 3 thou | 4.73e-8 mi |
| 4 thou | 6.31e-8 mi |
| 5 thou | 7.89e-8 mi |
| 6 thou | 9.47e-8 mi |
| 7 thou | 1.10e-7 mi |
| 8 thou | 1.26e-7 mi |
| 9 thou | 1.42e-7 mi |
| 10 thou | 1.58e-7 mi |
| 12 thou | 1.89e-7 mi |
| 15 thou | 2.37e-7 mi |
| 20 thou | 3.16e-7 mi |
| 25 thou | 3.95e-7 mi |
| 50 thou | 7.89e-7 mi |
| 100 thou | 0.000001578 mi |
| 200 thou | 0.000003157 mi |
| 300 thou | 0.000004735 mi |
| 500 thou | 0.000007891 mi |
| 1000 thou | 0.00001578 mi |
| 2000 thou | 0.00003157 mi |
| 5000 thou | 0.00007891 mi |
| 10000 thou | 0.0001578 mi |
What is a thou?
A thousandth of an inch, exactly 25.4 micrometers, and called a mil in American workshops — the same word the metric world uses for a millimeter, which is why a drawing marked "5 mil" is worth checking twice.
What is a mile?
Exactly 5,280 feet — a survivor of the Roman mille passus, rounded up by an English statute of 1593.
How many miles are in a thou?
One thou is 1.5783 × 10^-8 miles. Going the other way, one mile is 63360000 thou. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every length unit here
The whole group — 13 units with their symbols and the size of each one in meters — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a thou.
Source: NIST — international yard and pound agreement (inch = 25.4 mm exactly)
Cite this page
- APA
- Rule Calculator. (2026). Convert Thou to miles. Rule Calculator. https://rulecalculators.com/convert/thou-to-mile
- MLA
- "Convert Thou to miles." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/thou-to-mile.
- Chicago
- Rule Calculator. "Convert Thou to miles." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/thou-to-mile.
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Questions people actually ask
- How many miles are in a thou?
- 1.5783 × 10^-8. Exactly 5,280 feet — a survivor of the Roman mille passus, rounded up by an English statute of 1593.
- How do I convert miles back to thou?
- Divide by 1.5783 × 10^-8, or multiply by 63360000 — they are the same operation.
Other length conversions
Miles to thou — the same conversion the other way.