Square Inches to Square Centimeters
An instant square inches-to-square centimeters converter, with the formula and a reference table below.
| Square Inches | Square Centimeters |
|---|---|
| 1 in² | 6.4516 cm² |
| 2 in² | 12.9032 cm² |
| 3 in² | 19.3548 cm² |
| 5 in² | 32.258 cm² |
| 10 in² | 64.516 cm² |
| 25 in² | 161.29 cm² |
| 50 in² | 322.58 cm² |
| 100 in² | 645.16 cm² |
How to use
- Enter a value in the Square Inches field.
- The Square Centimeters figure appears immediately — no button to press.
- Typing in the Square Centimeters field converts back to Square Inches the same way.
- Use the reference table for the values that come up most often.
Square Inches to Square Centimeters formula
The factor from square inches to square centimeters is 6.4516.
cm² = in² × 6.4516
Why this factor: the square inch and the square centimeter are both defined against the square meter, so dividing one definition by the other gives 6.4516 directly. Both definitions are set out in full below.
To go the other way, divide by 6.4516 — or use the Square Centimeters to Square Inches converter, which is the same calculation reversed.
Worked example
Start with 50 in². Multiply by 6.4516 to get 322.58 cm².
50 in² × 6.4516 = 322.58 cm²
The converter above does this for any value you type, in either direction.
What is a square inch?
A square inch is the area of a one-inch square, used for small areas and pressure.
Definition: Exactly 0.00064516 square meter, following from the exact 25.4 mm inch.
Where it is used: Print and label areas, gasket and seal faces, and the denominator in psi.
What is a square centimeter?
A square centimeter is the area of a one-centimeter square.
Definition: Exactly 1×10⁻⁴ square meter — because 0.01 m squared is 0.0001 m².
Where it is used: Small surface areas, contact and cross-sectional areas, and pressure calculations.
Square Inches vs Square Centimeters
The square inch is an imperial unit while the square centimeter is a metric unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many square centimeters are in a square inch?
One square inch equals 6.4516 square centimeters.
What is the formula to convert square inches to square centimeters?
Multiply the number of square inches by 6.4516. To reverse it, divide by 6.4516 instead.
How do I convert square centimeters back to square inches?
Divide by 6.4516, which is the same as multiplying by 0.15500031.
How many square centimeters are in 10 square inches?
10 in² works out to 64.516 cm².
How is the square inch defined?
Exactly 0.00064516 square meter, following from the exact 25.4 mm inch.