---
title: "Square miles to Hectares — mi² to ha converter"
description: "1 square mile = 258.9988 hectares. Convert square miles to hectares with a full conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/square-miles-to-hectares/
site: "At One Place"
---

# Square miles to hectares

**1 square mile in hectares: 1 mi² = 258.9988 ha**

ha = mi² × 258.998811

To convert square miles to hectares, multiply by 258.998811. The table below gives the values people look up most often, and the converter works for any number.

## Square miles to hectares table

*Common square mile values converted to hectares.*

| Square miles | Hectares |
| --- | --- |
| 1 mi² | 258.9988 |
| 2 mi² | 517.9976 |
| 3 mi² | 776.9964 |
| 4 mi² | 1,035.9952 |
| 5 mi² | 1,294.9941 |
| 10 mi² | 2,589.9881 |
| 15 mi² | 3,884.9822 |
| 20 mi² | 5,179.9762 |
| 25 mi² | 6,474.9703 |
| 30 mi² | 7,769.9643 |
| 40 mi² | 10,359.952 |
| 50 mi² | 12,949.941 |
| 75 mi² | 19,424.911 |
| 100 mi² | 25,899.881 |
| 250 mi² | 64,749.703 |
| 500 mi² | 129,499.41 |
| 1,000 mi² | 258,998.81 |

## How the conversion works

The relationship is ha = mi² × 258.998811. Both units measure area, so the conversion is a fixed factor that never changes.

## Common questions

### How many hectares are in one square mile?

One square mile equals 258.9988 hectares. ha = mi² × 258.998811.

### How do you convert square miles to hectares?

Use ha = mi² × 258.998811. So 10 mi² is 2,589.9881 ha.

### How many square miles are in one hectare?

One hectare equals 0.003861 square miles, which is the reverse of the conversion above.

## Related pages

- [Hectares to Square miles](https://atoneplace.net/convert/hectares-to-square-miles/)
- [Square miles to Square meters](https://atoneplace.net/convert/square-miles-to-square-meters/)
- [Square miles to Square kilometers](https://atoneplace.net/convert/square-miles-to-square-km/)
- [Square miles to Acres](https://atoneplace.net/convert/square-miles-to-acres/)
- [Square miles to Square feet](https://atoneplace.net/convert/square-miles-to-square-feet/)

## Sources

- Guide for the Use of the International System of Units (SP 811) — NIST (https://www.nist.gov/pml/special-publication-811) [Public domain (US Government)]
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures (https://www.bipm.org/en/publications/si-brochure)
- Calculated on this page — At One Place (/about/)