Convert Square Thou to Square Chain
Convert square thous to square chains instantly. 1 square thou = 1.594225e-12 square chain — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Chain to Square Thou converter for the reverse conversion.
Units explained
Square Thou
A square thou is an imperial unit of area equal to 6.4516×10⁻¹⁰ m², identical to the square mil. The word 'thou' is short for 'thousandth' (of an inch).
Identical in value to the square mil; 'thou' is the British engineering term, 'mil' is the American term. Both refer to 1/1000 of an inch.
Square thous are used in British and Commonwealth engineering contexts where 'thou' is preferred over 'mil', particularly in mechanical engineering tolerance specifications.
Standardized via the 1959 International Yard and Pound Agreement.
Square Chain
A square chain is an imperial unit of area equal to approximately 404.686 m². It equals 1/10 of an acre.
Derived by squaring the chain (66 feet or 22 yards). The chain was defined by Edmund Gunter in 1620 specifically so that 10 square chains equal exactly one acre.
Square chains appear in US Public Land Survey System (PLSS) records and historical English property documents. The 10-to-1 ratio with acres made early survey arithmetic easier.
Defined by Edmund Gunter in 1620 specifically for surveying convenience.
Square Thou to Square Chain conversion formula
The relationship between square thous and square chains:
To convert square thous to square chains, multiply the value in square thous by 1.594225e-12. To reverse, multiply square chains by 6.27264e+11.
How to use this converter
Type a value into the calculator. The result in square chains 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 Chain to Square Thou converter for the reverse direction.
Step-by-step: convert square thous to square chains
- Write down the value in square thous (thou²).
- Multiply that value by the factor 1.594225e-12.
- The product is the equivalent value in square chains (ch²).
- To reverse, multiply the square chain value by 6.27264e+11.
Worked examples
Example 1 — Convert 1 thou² to ch²:
1 × 1.594225e-12 = 1.594225e-12 ch²
Example 2 — Convert 100 thou² to ch²:
100 × 1.594225e-12 = 1.594225e-10 ch²
Real-world example — Wavelengths across the spectrum
Optical and atomic-scale phenomena are routinely cross-converted between sub-micron units. A photon of wavelength 800 square thous can be re-expressed in square chains for direct comparison with another instrument's calibration data sheet.
800 thou² × 1.594225e-12 = 1.27538e-9 ch²
Real-world example — Molecular dimensions
The diameter of small molecular structures (around 2 square thous) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.
2 thou² × 1.594225e-12 = 3.18845e-12 ch²
Square Thou to Square Chain conversion table
Standard reference values for converting square thous to square chains:
| Square Thou [thou²] | Square Chain [ch²] |
|---|---|
| 0.01 | 1.594225e-14 |
| 0.1 | 1.594225e-13 |
| 1 | 1.594225e-12 |
| 2 | 3.18845e-12 |
| 3 | 4.782675e-12 |
| 4 | 6.3769e-12 |
| 5 | 7.971125e-12 |
| 10 | 1.594225e-11 |
| 20 | 3.18845e-11 |
| 30 | 4.782675e-11 |
| 40 | 6.3769e-11 |
| 50 | 7.971125e-11 |
| 100 | 1.594225e-10 |
| 500 | 7.971125e-10 |
| 1000 | 1.594225e-9 |
Frequently asked questions
How many square chains is 1 square thou?
How do I convert square thous to square chains?
How do I convert square chains back to square thous?
How many square chains is 100 square thous?
Popular area unit conversions
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Metric / SI (5 units)
Imperial / US Customary (14 units)
Sources & references
Conversion factor (1 thou² = 1.594225e-12 ch²) 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.