Convert Square Furlong to Rood
Convert square furlongs to roods instantly. 1 square furlong = 40 rood — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Rood to Square Furlong converter for the reverse conversion.
Units explained
Square Furlong
A square furlong is an imperial unit of area equal to exactly 40,468.564 m², or 10 acres.
Derived by squaring the furlong (660 feet or 1/8 mile). The furlong itself comes from medieval English 'furrow long', the length of a plowed furrow.
Square furlongs are rarely used today. The unit appears occasionally in historical English farming records and in some horseracing contexts (though usually as length, not area).
Medieval English origin; standardized via the 1959 International Yard and Pound Agreement.
Rood
A rood is an imperial unit of area equal to approximately 1011.71 m², or 1/4 of an acre. It was historically used in England and parts of the British Empire.
Defined as one-quarter of an acre; historically used in medieval English farming as the area one ox could plow in a day. The word relates to 'rod' as a measure of length used in plot dimensions.
Roods appear in historical English farming records, parish records, and old property deeds. The unit is functionally obsolete today.
Medieval English farming origin; standardized via the 1959 International Yard and Pound Agreement.
Square Furlong to Rood conversion formula
The relationship between square furlongs and roods:
To convert square furlongs to roods, multiply the value in square furlongs by 40. To reverse, multiply roods by 0.025.
How to use this converter
Type a value into the calculator. The result in roods updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Rood to Square Furlong converter for the reverse direction.
Step-by-step: convert square furlongs to roods
- Write down the value in square furlongs (fur²).
- Multiply that value by the factor 40.
- The product is the equivalent value in roods (rood).
- To reverse, multiply the rood value by 0.025.
Worked examples
Example 1 — Convert 1 fur² to rood:
1 × 40 = 40 rood
Example 2 — Convert 100 fur² to rood:
100 × 40 = 4000 rood
Real-world example — Road-sign distances across systems
A 100-square furlong road sign converts cleanly into roods — exactly the conversion drivers planning trips abroad rely on when reading road signs in a different measurement system.
100 fur² × 40 = 4000 rood
Real-world example — Endurance race distances
A 50-square furlong cycling or running race converts to a recognizable distance in roods. Endurance athletes coming from a different measurement system use this conversion to compare training plans across regions.
50 fur² × 40 = 2000 rood
Real-world example — Maritime exclusion zone
A 200-square furlong exclusion zone (a common maritime boundary) converts to a different value in roods that's useful when describing the same zone in everyday land-distance units.
200 fur² × 40 = 8000 rood
Square Furlong to Rood conversion table
Standard reference values for converting square furlongs to roods:
| Square Furlong [fur²] | Rood [rood] |
|---|---|
| 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 roods is 1 square furlong?
How do I convert square furlongs to roods?
How do I convert roods back to square furlongs?
How many roods is 100 square furlongs?
Popular area unit conversions
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Metric / SI (5 units)
Imperial / US Customary (14 units)
Sources & references
Conversion factor (1 fur² = 40 rood) 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.