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Square centimeters to Square inches (cm² to in²)
Convert square centimeters to square inches: 1 cm² = 0.155 in². Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.
Formula
1 cm² = 0.155 in²
square inches = square centimeters × 0.15500031 — reverse: square centimeters = square inches × 6.4516
The factor is derived from the SI definitions of both units (base unit: m2) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.
Worked examples
- 5 cm² = 0.775002 in²
- 12.5 cm² = 1.9375 in²
- 100 cm² = 15.5 in²
Square centimeters to square inches conversion table
| Square centimeters (cm²) | Square inches (in²) |
|---|---|
| 1 | 0.155 |
| 2 | 0.310001 |
| 3 | 0.465001 |
| 4 | 0.620001 |
| 5 | 0.775002 |
| 6 | 0.930002 |
| 7 | 1.085 |
| 8 | 1.24 |
| 9 | 1.395 |
| 10 | 1.55 |
| 15 | 2.325 |
| 20 | 3.10001 |
| 25 | 3.87501 |
| 30 | 4.65001 |
| 40 | 6.20001 |
| 50 | 7.75002 |
| 75 | 11.625 |
| 100 | 15.5 |
| 200 | 31.0001 |
| 250 | 38.7501 |
| 500 | 77.5002 |
| 1000 | 155 |
FAQ
How many square inches are in one square centimeter?
1 cm² = 0.155 in². The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.
What is the formula to convert square centimeters to square inches?
Multiply the value in square centimeters by 0.15500031: square inches = square centimeters × 0.15500031. For example, 5 cm² = 0.775002 in².
How do I convert square inches back to square centimeters?
Multiply by the inverse factor 6.4516 (square centimeters = square inches × 6.4516), or use the square inches-to-square centimeters page.
Related conversions
Machine access
- API:
GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=cm2&to_unit=in2 - MCP: server
https://tttkmbb.com/mcp, toolconvert_unitswith{"value":5,"from_unit":"cm2","to_unit":"in2"} - Markdown: https://tttkmbb.com/conversion/square-cm-to-square-inches.md · JSON: https://tttkmbb.com/conversion/square-cm-to-square-inches.json (add
?value=for a result) · Units: /api/v1/units?quantity=area - OpenAPI operationId:
convert_units. Freshness:static. Authentication: none.