Convert Inch to US Survey Foot
Convert inches to us survey feet instantly. 1 inch = 0.0833331667 us survey foot — use the live calculator, the exact formula, a conversion table and worked examples. Also check the US Survey Foot to Inch converter for the reverse conversion.
Units explained
Inch
An inch is an Imperial and US customary unit of length defined since 1959 as exactly 25.4 millimeters (0.0254 meters). It is still the standard small unit of length in the United States, the United Kingdom (informally), and a few other countries.
The inch derives from the Roman uncia (one-twelfth of a foot) and survived through Anglo-Saxon and medieval English measurement systems. Various definitions persisted regionally until the 1959 International Yard and Pound Agreement standardized the inch globally as exactly 25.4 mm.
Inches are used in the US and UK for body height, screen sizes (TVs, monitors, phones), tire sizes, plumbing, lumber, paper sizes (US Letter is 8.5 × 11 in), and most consumer product specifications in the United States.
Anglo-Saxon origin (predating 1066); standardized to 25.4 mm exactly by the International Yard and Pound Agreement of 1959, signed by the US, UK, Canada, Australia, New Zealand, and South Africa.
US Survey Foot
The US Survey Foot is a legacy unit of length defined as exactly 1200/3937 meters (approximately 0.3048006 m). It differs from the modern international foot by about 2 parts per million.
Established in the United States by the Mendenhall Order of 1893, which defined the foot in terms of the meter as 1200/3937 m. The US continued using this value for surveying even after the 1959 International Yard and Pound Agreement standardized the international foot at exactly 0.3048 m.
Used in US land surveying, geodetic measurements, state plane coordinate systems, and legal land descriptions. The US Survey Foot was officially deprecated by NIST and NOAA effective December 31, 2022, with the international foot becoming the sole US standard. Legacy data and recorded land surveys still reference it.
Mendenhall Order of 1893 defined the foot as 1200/3937 m; persisted in US surveying after 1959; officially deprecated by NIST/NOAA as of December 31, 2022.
Inch to US Survey Foot conversion formula
Note: this conversion uses a generally accepted modern value. Historical and regional definitions of this unit varied across times and places.
The relationship between inches and us survey feet:
To convert inches to us survey feet, multiply the value in inches by 0.0833331667. To reverse, multiply us survey feet by 12.000024.
How to use this converter
Type a value into the calculator. The result in us survey feet updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the US Survey Foot to Inch converter for the reverse direction.
Step-by-step: convert inches to us survey feet
- Write down the value in inches (in).
- Multiply that value by the factor 0.0833331667.
- The product is the equivalent value in us survey feet (sft).
- To reverse, multiply the us survey foot value by 12.000024.
Worked examples
Example 1 — Convert 1 in to sft:
1 × 0.0833331667 = 0.0833331667 sft
Example 2 — Convert 100 in to sft:
100 × 0.0833331667 = 8.3333166667 sft
Real-world example — Children's height milestones
A 150-inch-tall child measures a value in us survey feet that's commonly used for theme-park ride height requirements when travelling between countries that use different measurement units.
150 in × 0.0833331667 = 12.499975 sft
Real-world example — Body height conversion
You enter your height as 180 inches into an international job or visa application. The form then asks for the same value in us survey feet — converting between these adjacent units is one of the most-used length conversions globally.
180 in × 0.0833331667 = 14.99997 sft
Real-world example — Furniture and large objects
A 72-inch piece of furniture converts to a value in us survey feet that's easier to mentally compare with room dimensions. This is the typical workflow when shopping internationally and product specs use a different unit than your room measurements.
72 in × 0.0833331667 = 5.999988 sft
Inch to US Survey Foot conversion table
Standard reference values for converting inches to us survey feet:
| Inch [in] | US Survey Foot [sft] |
|---|---|
| 0.01 | 0.0008333317 |
| 0.1 | 0.0083333167 |
| 1 | 0.0833331667 |
| 2 | 0.1666663333 |
| 3 | 0.2499995 |
| 4 | 0.3333326667 |
| 5 | 0.4166658333 |
| 10 | 0.8333316667 |
| 20 | 1.6666633333 |
| 30 | 2.499995 |
| 40 | 3.3333266667 |
| 50 | 4.1666583333 |
| 100 | 8.3333166667 |
| 500 | 41.6665833333 |
| 1000 | 83.3331666667 |
Frequently asked questions
How many us survey feet is 1 inch?
How do I convert inches to us survey feet?
How do I convert us survey feet back to inches?
How many us survey feet is 100 inches?
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Atomic / Physics (6 units)
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Sources & references
Conversion factor (1 in = 0.0833331667 sft) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.