Convert Square Perch to Square Mile
Convert square perches to square miles instantly. 1 square perch = 9.765625e-6 square mile — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Mile to Square Perch converter for the reverse conversion.
Units explained
Square Perch
A square perch is identical to a square rod, equal to approximately 25.293 m². 'Perch' is the older English regional name for the same unit.
Identical in value to square rod and square pole; differs only in regional naming preference. 'Perch' is more commonly used in British and Irish historical contexts.
Square perches survive in some historical British property records, particularly in Ireland where the unit had legal status until the metric transition.
Standardized via the 1959 International Yard and Pound Agreement.
Square Mile
A square mile is an imperial unit of area equal to exactly 2,589,988.110336 m². It is used for measuring large land areas in the United States and the United Kingdom.
Derived by squaring the statute mile (5,280 feet). The mile was standardized via the 1959 International Yard and Pound Agreement.
Square miles are used for US and UK regional geography (county areas, lake sizes, large parks), national statistics, and military range descriptions. 1 mi² = 640 acres = 2.589988 km².
Mile dates to Roman antiquity; modern exact value standardized in 1959.
Square Perch to Square Mile conversion formula
The relationship between square perches and square miles:
To convert square perches to square miles, multiply the value in square perches by 9.765625e-6. To reverse, multiply square miles by 102400.
How to use this converter
Type a value into the calculator. The result in square miles updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Square Mile to Square Perch converter for the reverse direction.
Step-by-step: convert square perches to square miles
- Write down the value in square perches (perch²).
- Multiply that value by the factor 9.765625e-6.
- The product is the equivalent value in square miles (mi²).
- To reverse, multiply the square mile value by 102400.
Worked examples
Example 1 — Convert 1 perch² to mi²:
1 × 9.765625e-6 = 9.765625e-6 mi²
Example 2 — Convert 100 perch² to mi²:
100 × 9.765625e-6 = 0.0009765625 mi²
Square Perch to Square Mile conversion table
Standard reference values for converting square perches to square miles:
| Square Perch [perch²] | Square Mile [mi²] |
|---|---|
| 0.01 | 9.765625e-8 |
| 0.1 | 9.765625e-7 |
| 1 | 9.765625e-6 |
| 2 | 1.953125e-5 |
| 3 | 2.929687e-5 |
| 4 | 3.90625e-5 |
| 5 | 4.882813e-5 |
| 10 | 9.765625e-5 |
| 20 | 0.0001953125 |
| 30 | 0.0002929687 |
| 40 | 0.000390625 |
| 50 | 0.0004882812 |
| 100 | 0.0009765625 |
| 500 | 0.0048828125 |
| 1000 | 0.009765625 |
Frequently asked questions
How many square miles is 1 square perch?
How do I convert square perches to square miles?
How do I convert square miles back to square perches?
How many square miles is 100 square perches?
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Metric / SI (5 units)
Imperial / US Customary (14 units)
Sources & references
Conversion factor (1 perch² = 9.765625e-6 mi²) 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 Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.