Square Millimeters to Square Inches (mm² to in²)
Free online square millimeter to square inch converter. Type a value, get an instant exact result — plus the formula, a ready-made conversion table, and reverse conversion.
AREA CONVERTER — INSTANT RESULT
Formula: multiply the square millimeter value by 0.0015500031 — i.e. in² = mm² × 0.0015500031
Quick check: 1 mm² = 0.0015500031 in²
Quick check: 1 mm² = 0.0015500031 in²
Square Millimeters to Square Inches conversion table
| Square Millimeters (mm²) | Square Inches (in²) |
|---|---|
| 1 mm² | 0.0015500031 in² |
| 2 mm² | 0.0031000062 in² |
| 3 mm² | 0.0046500093 in² |
| 4 mm² | 0.0062000124 in² |
| 5 mm² | 0.0077500155 in² |
| 6 mm² | 0.0093000186 in² |
| 7 mm² | 0.010850022 in² |
| 8 mm² | 0.012400025 in² |
| 9 mm² | 0.013950028 in² |
| 10 mm² | 0.015500031 in² |
| 15 mm² | 0.023250047 in² |
| 20 mm² | 0.031000062 in² |
| 25 mm² | 0.038750078 in² |
| 30 mm² | 0.046500093 in² |
| 40 mm² | 0.062000124 in² |
| 50 mm² | 0.077500155 in² |
| 75 mm² | 0.11625023 in² |
| 100 mm² | 0.15500031 in² |
| 250 mm² | 0.38750078 in² |
| 500 mm² | 0.77500155 in² |
| 1,000 mm² | 1.5500031 in² |
How to convert square millimeters to square inches
To convert square millimeters to square inches, multiply the amount in square millimeters by 0.0015500031. For example, 10 mm² = 0.015500031 in². To convert in the other direction, divide by the same factor, or use the ⇄ swap button above.
Convert between metric and imperial/US land area units, including the acre (43,560 ft² exactly) and hectare (10,000 m²) used worldwide for land measurement.
Frequently asked questions
How many square inches are in one square millimeter?
One square millimeter is exactly 0.0015500031 square inches.
How do I convert mm² to in²?
Multiply the mm² value by 0.0015500031 to get in². The converter at the top of this page does this automatically and works in both directions.
How much is 100 square millimeters in square inches?
100 square millimeters equals 0.15500031 square inches.