Why the factor is 2.58998811
A square mile is the area of a square with side 1 statute mile. Since 1 mile = 1.609344 kilometers, then:
1 mi² = (1.609344 km)² = 1.609344 × 1.609344 km² = 2.589988110336 km²
Most websites round this to 2.59 km², which is okay for everyday use. This tool keeps the exact figure but displays reasonable decimals.
Formulas
km² = mi² × 2.58998811
mi² = km² ÷ 2.58998811
FAQ
1. Is this the same as square nautical miles?
No. Nautical miles and statute miles are different. This page uses the US/UK statute mile (1,609.344 m).
2. Can I use this for GIS / mapping?
Yes. Many datasets in the US use mi², while international/UN datasets use km². Use this to switch between them.
3. What precision should I report?
For large regions, 2 decimals in km² is often enough. For engineering / cadastral work, retain at least 4 decimals.
Formula (LaTeX) + variables + units
This section shows the formulas used by the calculator engine, plus variable definitions and units.
Formula (extracted LaTeX)
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Formula (extracted text)
1 mi² = (1.609344 km)² = 1.609344 × 1.609344 km² = 2.589988110336 km²
Formula (extracted text)
km² = mi² × 2.58998811 mi² = km² ÷ 2.58998811
Variables and units
- No variables provided in audit spec.
Sources (authoritative):
- NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures - NIST — SI units — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/owm/metric-si/si-units
Changelog
Version: 0.1.0-draft
Last code update: 2026-01-19
Last code update: 2026-01-19
0.1.0-draft · 2026-01-19
- Initial audit spec draft generated from HTML extraction (review required).
- Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
- Confirm sources are authoritative and relevant to the calculator methodology.