Photometry
sbtoasb
Convert stilbs (sb) to apostilbs (asb).
Factor1 sb = 31415.93 asb
Converter
sb
Accepts numbers or expressions, e.g. 150 + 14.7
Result
asb
Rendered to 6 significant figures.
Formula
Formula
asb = sb × 31415.93
Multiply any value in stilbs by 31415.93 to obtain the value in apostilbs.
Worked example
Convert 1 sb to asb.
- 01Start with 1 sb.
- 02Multiply by the conversion factor: 1 × 31415.93 = 31415.9 asb.
Result1 sb = 31415.9 asb
Conversion table
| sb | asb |
|---|---|
| 1 | 31416 |
| 2 | 62832 |
| 5 | 1.5708e+5 |
| 10 | 3.1416e+5 |
| 20 | 6.2832e+5 |
| 50 | 1.5708e+6 |
| 100 | 3.1416e+6 |
| 200 | 6.2832e+6 |
| 500 | 1.5708e+7 |
| 1000 | 3.1416e+7 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from sb to asb?
1 sb equals 31415.93 asb. To convert, multiply the value in stilbs by 31415.93.
How do I convert 1 sb to asb?
1 sb = 31415.9 asb. For any value, multiply by 31415.93.
How do I convert asb back to sb?
Divide by the same factor — or equivalently, multiply by 3.183099e-5. So 1 asb = 3.1831e-5 sb.
When would I need to convert stilb to apostilb?
Luminance conversions between sb 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).