Convert square inches to square centimeters in seconds
1 sq in x 6.4516 = 6.4516 sq cm
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Ever tried buying a phone case from an international website only to find the dimensions in unfamiliar units? Or maybe you’ve stared at a DIY furniture manual mixing imperial and metric measurements? That’s where square inches to square centimeters conversion becomes your best friend. This guide breaks down everything from quick calculations to why these units matter in our globalized world.
Unit definitions
What is a square inch (sq in)?
- Description: The area of a square with 1-inch sides
- Symbol: in²
- Common uses: Measuring screen sizes, paper dimensions, small surface areas in US products
- Definition: 1 sq in = 1 in × 1 in = 2.54 cm × 2.54 cm = 6.4516 cm²
What is a square centimeter (sq cm)?
- Description: The area of a square with 1-centimeter sides
- Symbol: cm²
- Common uses: Medical imaging measurements, electronic components, international packaging
- Definition: 1 sq cm = 0.155 sq in
Conversion formula
The golden rule:
1 square inch = 6.4516 square centimeters
Multiply square inches by 6.4516 to get centimeters squared.
Need to go the other way?
1 square centimeter = 0.155 square inches
Divide cm² by 6.4516 (or multiply by 0.155) for sq in.
Example calculations
- Converting a 4 sq in photo frame to metric:
4 × 6.4516 = 25.8064 cm²
(That’s slightly larger than a standard postcard) - Translating 100 cm² fabric to imperial:
100 ÷ 6.4516 ≈ 15.5 sq in
(Roughly the size of a smartphone screen)
Conversion tables
Square inches to square centimeters
| Square inches | Square centimeters |
|---|---|
| 1 | 6.45 |
| 2 | 12.90 |
| 3 | 19.35 |
| 4 | 25.81 |
| 5 | 32.26 |
| 6 | 38.71 |
| 7 | 45.16 |
| 8 | 51.61 |
| 9 | 58.06 |
| 10 | 64.52 |
Square centimeters to square inches
| Square centimeters | Square inches |
|---|---|
| 10 | 1.55 |
| 20 | 3.10 |
| 30 | 4.65 |
| 40 | 6.20 |
| 50 | 7.75 |
| 60 | 9.30 |
| 70 | 10.85 |
| 80 | 12.40 |
| 90 | 13.95 |
| 100 | 15.50 |
Historical background
The square inch has roots in the British Imperial system, tracing back to medieval English units. Fun fact—the original inch was based on three barleycorns laid end-to-end! The square centimeter emerged during teh French Revolution as part of the metric system’s push for decimal-based measurements. While inches still rule in some US industries, cm² dominates globally—about 95% of the world uses metric units daily.
Interesting facts
- A standard credit card measures ~46 sq in (300 cm²)
- iPhone screen sizes range from 9 to 14 sq in (58-90 cm²)
- 1 square meter contains 10,000 cm² but only 1,550 sq in
- Postage stamps are typically 1-2 sq in (6.5-12.9 cm²)
- The metric system’s decimal base makes cm² conversions 10x easier than imperial fractions
FAQ
This conversion is essential for international projects, engineering designs, and comparing product dimensions between countries using imperial and metric systems.
Yes—each area conversion uses unique ratios. Always verify the correct multiplier for your specific units.
The formula remains precise, but rounding errors can accumulate. For critical applications, use exact values without rounding intermediate steps.
Common in electronics manufacturing, print design, and appliance specifications where compact measurements matter.
Yes, both terms describe area measurements—1 cm² equals a square with 1 cm sides.