Convert Furlong to Perch
Convert furlongs to perches instantly. 1 furlong = 40 perch — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Perch to Furlong converter for the reverse conversion.
Units explained
Furlong
A furlong is an Imperial unit of length equal to 660 feet, or exactly one eighth of a mile (about 201.17 m). It is the longest unit in the traditional English farm-and-survey system.
The furlong derives from Old English furh (furrow) + lang (long) — originally the length of a furrow in a typical medieval English open field. Standardised at 660 feet (= 10 chains = 220 yards = 1/8 mile) in medieval times.
Furlongs are the standard distance unit in horse racing (e.g., 'The race is 8 furlongs'), historical English farming and surveying, and occasional poetic or rhetorical usage. Modern racing courses worldwide list distances in furlongs.
Medieval English farming origin; standardised at 660 feet; remains the official distance unit in flat-racing thoroughbred horse races worldwide.
Perch
A perch is an Imperial unit of length identical to the rod — 16.5 feet (about 5.03 m). The names 'rod', 'perch', and 'pole' all refer to the same surveying unit and differ only by regional preference.
Like the rod, the perch derives from medieval English land-surveying. The name 'perch' was particularly common in legal land descriptions in Ireland and parts of the UK.
Perches appear in legacy land descriptions in Ireland, the UK, and historical US documents. Modern usage is rare.
Medieval English surveying origin; identical to the rod since 1620; became exact via the 1959 International Yard and Pound Agreement.
Furlong to Perch conversion formula
The relationship between furlongs and perches:
To convert furlongs to perches, multiply the value in furlongs by 40. To reverse, multiply perches by 0.025.
How to use this converter
Type a value into the calculator. The result in perches updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Perch to Furlong converter for the reverse direction.
Step-by-step: convert furlongs to perches
- Write down the value in furlongs (fur).
- Multiply that value by the factor 40.
- The product is the equivalent value in perches (perch).
- To reverse, multiply the perch value by 0.025.
Worked examples
Example 1 — Convert 1 fur to perch:
1 × 40 = 40 perch
Example 2 — Convert 100 fur to perch:
100 × 40 = 4000 perch
Furlong to Perch conversion table
Standard reference values for converting furlongs to perches:
| Furlong [fur] | Perch [perch] |
|---|---|
| 0.01 | 0.4 |
| 0.1 | 4 |
| 1 | 40 |
| 2 | 80 |
| 3 | 120 |
| 4 | 160 |
| 5 | 200 |
| 10 | 400 |
| 20 | 800 |
| 30 | 1200 |
| 40 | 1600 |
| 50 | 2000 |
| 100 | 4000 |
| 500 | 20000 |
| 1000 | 40000 |
Frequently asked questions
How many perches is 1 furlong?
How do I convert furlongs to perches?
How do I convert perches back to furlongs?
How many perches is 100 furlongs?
Popular length unit conversions
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Metric / SI (4 units)
Imperial / US Customary (26 units)
Sources & references
Conversion factor (1 fur = 40 perch) 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.