Convert Square Perch to Rood
Convert square perches to roods instantly. 1 square perch = 0.025 rood — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Rood 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.
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 Perch to Rood conversion formula
The relationship between square perches and roods:
To convert square perches to roods, multiply the value in square perches by 0.025. To reverse, multiply roods by 40.
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 Perch converter for the reverse direction.
Step-by-step: convert square perches to roods
- Write down the value in square perches (perch²).
- Multiply that value by the factor 0.025.
- The product is the equivalent value in roods (rood).
- To reverse, multiply the rood value by 40.
Worked examples
Example 1 — Convert 1 perch² to rood:
1 × 0.025 = 0.025 rood
Example 2 — Convert 100 perch² to rood:
100 × 0.025 = 2.5 rood
Square Perch to Rood conversion table
Standard reference values for converting square perches to roods:
| Square Perch [perch²] | Rood [rood] |
|---|---|
| 0.01 | 0.00025 |
| 0.1 | 0.0025 |
| 1 | 0.025 |
| 2 | 0.05 |
| 3 | 0.075 |
| 4 | 0.1 |
| 5 | 0.125 |
| 10 | 0.25 |
| 20 | 0.5 |
| 30 | 0.75 |
| 40 | 1 |
| 50 | 1.25 |
| 100 | 2.5 |
| 500 | 12.5 |
| 1000 | 25 |
Frequently asked questions
How many roods is 1 square perch?
How do I convert square perches to roods?
How do I convert roods back to square perches?
How many roods is 100 square perches?
Popular area unit conversions
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Metric / SI (5 units)
Imperial / US Customary (14 units)
Sources & references
Conversion factor (1 perch² = 0.025 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 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.