Convert Barn to Square Centimeter
Convert barns to square centimeters instantly. 1 barn = 1e-24 square centimeter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Centimeter to Barn converter for the reverse conversion.
Units explained
Barn
A barn is a scientific unit of area equal to exactly 10⁻²⁸ m² (100 fm²). It is used in nuclear and particle physics to express interaction cross-sections.
Named in 1942 at Purdue University by physicists working on the Manhattan Project. The name comes from the phrase 'big as a barn' — uranium nuclei have cross-sections this large, which physicists initially considered surprisingly large for nuclear targets.
Barns and their submultiples (millibarn, microbarn, nanobarn, picobarn, femtobarn) are the standard units for cross-section measurements in nuclear physics, high-energy physics, and accelerator experiments. The Higgs boson production cross-section at the LHC is in the picobarn range.
Named in 1942 during the Manhattan Project; adopted internationally in particle physics.
Square Centimeter
A square centimeter is a metric unit of area equal to 10⁻⁴ m² (1 cm × 1 cm). It is widely used in everyday measurement, lab work, and small-area applications.
Derived by squaring the centimeter (1/100 of a meter). The centi- prefix comes from the Latin 'centum' (hundred).
Square centimeters express the cross-sectional area of pipes and cables, the surface area of small everyday objects, biological tissue samples, and many engineering quantities. The SI unit for medical/pharmaceutical dose-per-area is often expressed in cm².
Centimeter has been part of the metric system since 1795.
Barn to Square Centimeter conversion formula
The relationship between barns and square centimeters:
To convert barns to square centimeters, multiply the value in barns by 1e-24. To reverse, multiply square centimeters by 1e+24.
How to use this converter
Type a value into the calculator. The result in square centimeters updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Square Centimeter to Barn converter for the reverse direction.
Step-by-step: convert barns to square centimeters
- Write down the value in barns (b).
- Multiply that value by the factor 1e-24.
- The product is the equivalent value in square centimeters (cm²).
- To reverse, multiply the square centimeter value by 1e+24.
Worked examples
Example 1 — Convert 1 b to cm²:
1 × 1e-24 = 1e-24 cm²
Example 2 — Convert 100 b to cm²:
100 × 1e-24 = 1e-22 cm²
Real-world example — Sub-visible-light wavelength
500 barns (the green-yellow visible band) equals 0.5 square centimeters — the canonical conversion in optics between wavelength specifications and micron-scale lens-coating thicknesses.
500 b × 1e-24 = 5e-22 cm²
Real-world example — Spanning sub-micron to micron scale
Crossing from barns to square centimeters is the everyday workflow of microscopy and semiconductor engineering — a measurement of 1000 barns translates to a much more compact value in square centimeters that fits the scale of biological cells and process nodes.
1000 b × 1e-24 = 1e-21 cm²
Barn to Square Centimeter conversion table
Standard reference values for converting barns to square centimeters:
| Barn [b] | Square Centimeter [cm²] |
|---|---|
| 0.01 | 1e-26 |
| 0.1 | 1e-25 |
| 1 | 1e-24 |
| 2 | 2e-24 |
| 3 | 3e-24 |
| 4 | 4e-24 |
| 5 | 5e-24 |
| 10 | 1e-23 |
| 20 | 2e-23 |
| 30 | 3e-23 |
| 40 | 4e-23 |
| 50 | 5e-23 |
| 100 | 1e-22 |
| 500 | 5e-22 |
| 1000 | 1e-21 |
Frequently asked questions
How many square centimeters is 1 barn?
How do I convert barns to square centimeters?
How do I convert square centimeters back to barns?
How many square centimeters is 100 barns?
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Sources & references
Conversion factor (1 b = 1e-24 cm²) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.