Length · Unit Converter

Convert Rood to Square Mil

Convert roods to square mils instantly. 1 rood = 1.56816e+12 square mil — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Mil to Rood converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Girish V Kulkarni Ph.D.
Length category 2 min read Published Last reviewed Updated

Units explained

Imperial / US Customary

Rood

What is a 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.

Origin of the rood

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.

Where it is used

Roods appear in historical English farming records, parish records, and old property deeds. The unit is functionally obsolete today.

When and where it was developed

Medieval English farming origin; standardized via the 1959 International Yard and Pound Agreement.

Imperial / US Customary

Square Mil

What is a square mil?

A square mil is an imperial unit of area equal to 6.4516×10⁻¹⁰ m². It is widely used in printed circuit board (PCB) design and electronics manufacturing.

Origin of the square mil

Derived by squaring the mil (1 mil = 1/1000 of an inch = 0.0254 mm). Standardized via the 1959 International Yard and Pound Agreement.

Where it is used

Square mils are the standard unit for PCB trace cross-sections, pad areas, and component pitches in US-localized electronic design software and datasheets.

When and where it was developed

Standardized via the 1959 International Yard and Pound Agreement.

Rood to Square Mil conversion formula

The relationship between roods and square mils:

1 rood = 1.56816e+12 mil²
1 mil² = 6.3769e-13 rood

To convert roods to square mils, multiply the value in roods by 1.56816e+12. To reverse, multiply square mils by 6.3769e-13.

How to use this converter

Type a value into the calculator. The result in square mils 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 Mil to Rood converter for the reverse direction.

Step-by-step: convert roods to square mils

  1. Write down the value in roods (rood).
  2. Multiply that value by the factor 1.56816e+12.
  3. The product is the equivalent value in square mils (mil²).
  4. To reverse, multiply the square mil value by 6.3769e-13.

Worked examples

Example 1 — Convert 1 rood to mil²:
1 × 1.56816e+12 = 1.56816e+12 mil²

Example 2 — Convert 100 rood to mil²:
100 × 1.56816e+12 = 1.56816e+14 mil²

Real-world example — Kilometres to wavelengths

One rood equals one trillion square mils — a conversion physics teachers use to convey the gulf between everyday geographic and atomic scales.

1 rood × 1.56816e+12 = 1.56816e+12 mil²

Real-world example — Geographic to wavelength scale

One rood equals one trillion square mils — illustrating the 12-order-of-magnitude span between geographic distance and atomic-feature scales.

1 rood × 1.56816e+12 = 1.56816e+12 mil²

Rood to Square Mil conversion table

Standard reference values for converting roods to square mils:

Rood [rood]Square Mil [mil²]
0.011.56816e+10
0.11.56816e+11
11.56816e+12
23.13632e+12
34.70448e+12
46.27264e+12
57.8408e+12
101.56816e+13
203.13632e+13
304.70448e+13
406.27264e+13
507.8408e+13
1001.56816e+14
5007.8408e+14
10001.56816e+15

Frequently asked questions

How many square mils is 1 rood?
1 rood equals 1.56816e+12 square mil.
How do I convert roods to square mils?
Multiply the value in roods by 1.56816e+12 to get square mils.
How do I convert square mils back to roods?
Multiply the value in square mils by 6.3769e-13, or use the Square Mil to Rood converter.
How many square mils is 100 roods?
100 roods equals 1.56816e+14 square mils, because 100 × 1.56816e+12 = 1.56816e+14.

Convert Rood to other area units

Show all Rood conversions

Sources & references

Conversion factor (1 rood = 1.56816e+12 mil²) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.