Photometry
cd/m²toasb
Convert candelas per square metre (cd/m²) to apostilbs (asb).
Factor1 cd/m² = 3.141593 asb
Converter
cd/m²
Accepts numbers or expressions, e.g. 150 + 14.7
Result
asb
Rendered to 6 significant figures.
Formula
Formula
asb = cd/m² × 3.141593
Multiply any value in candelas per square metre by 3.141593 to obtain the value in apostilbs.
Worked example
Convert 100 cd/m² to asb.
- 01Start with 100 cd/m².
- 02Multiply by the conversion factor: 100 × 3.141593 = 314.159 asb.
Result100 cd/m² = 314.159 asb
Conversion table
| cd/m² | asb |
|---|---|
| 1 | 3.1416 |
| 2 | 6.2832 |
| 5 | 15.708 |
| 10 | 31.416 |
| 20 | 62.832 |
| 50 | 157.08 |
| 100 | 314.16 |
| 200 | 628.32 |
| 500 | 1570.8 |
| 1000 | 3141.6 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from cd/m² to asb?
1 cd/m² equals 3.141593 asb. To convert, multiply the value in candelas per square metre by 3.141593.
How do I convert 1 cd/m² to asb?
1 cd/m² = 3.14159 asb. For any value, multiply by 3.141593.
How do I convert asb back to cd/m²?
Divide by the same factor — or equivalently, multiply by 0.3183099. So 1 asb = 0.31831 cd/m².
When would I need to convert candela per square metre to apostilb?
Luminance conversions between cd/m² and asb are used in display engineering, road and traffic-signal design, and photometric measurement of luminous surfaces. cd/m² (nit) is the SI standard; foot-lambert and stilb appear in legacy datasheets and specialist optics work.
Is the conversion exact?
The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).