Convert Stilbs to Apostilbs (sb to asb)
1 stilb (sb) = 31415.92654 apostilbs (asb). 1 asb = 0.00003183098862 sb. Example: 15 sb = 15 × 31415.92654 = 471238.898 asb.
Also searched as stilbs to asb, stilbs in asb, stilbs into apostilbs, sb to asb, sb in apostilbs, sb into apostilb, stilb to apostilb, sb to apostilbs converter and how many apostilbs in a stilb.
1 sb = 31415.92654 asb
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk stilb to apostilb converter to paste a column from Excel.
How to Convert Stilb to Apostilb
- 1 sb = 31415.92654 asb
- 1 asb = 0.00003183098862 sb
- Example: convert 15 sb to asb: 15 sb = 15 × 31415.92654 asb = 471238.898 asb
Formula
asb = sb × 31415.9265359
Derivation from SI units:
- 1 sb = 1 cd/cm² = 10⁴ cd/m².
- 1 asb = (1/π) cd/m² ≈ 0.3183 cd/m².
- 1 sb = 10000 cd/m² ÷ 0.3183098861838 cd/m² per asb = 31415.9265359 asb
Both units are defined exactly, so the factor is exact. Stilb definition: stilb; Apostilb definition: apostilb.
Worked examples
- A reading of 2 sb converts to 62831.85307 asb.
2 sb × 31415.92654 = 62831.85307 asb - A value of 20 sb is 628318.5307 asb.
20 sb × 31415.92654 = 628318.5307 asb
Stilb to Apostilb conversion table
| Stilbs (sb) | Apostilbs (asb) |
|---|---|
| 0.1 sb | 3141.592654 asb |
| 0.5 sb | 15707.96327 asb |
| 1 sb | 31415.92654 asb |
| 2 sb | 62831.85307 asb |
| 5 sb | 157079.6327 asb |
| 10 sb | 314159.2654 asb |
| 20 sb | 628318.5307 asb |
| 50 sb | 1570796.327 asb |
| 100 sb | 3141592.654 asb |
| 1000 sb | 31415926.54 asb |
Where it's used
Stilbs are used for older optics and lamp data, while apostilbs appear in ophthalmic perimetry. Both measure luminance (brightness of a surface or screen), so the conversion is a fixed factor.
Stilb to other luminance units
| Conversion | 1 sb equals |
|---|---|
| stilb to apostilb | 31415.92654 asb |
| stilb to nit | 10000 cd/m² |
| stilb to foot-lambert | 2918.63508 fL |
| stilb to candela per square foot | 929.0304 cd/ft² |
| stilb to candela per square inch | 6.4516 cd/in² |
| stilb to lambert | 3.141592654 L |
Frequently asked questions
How many apostilbs are in 1 stilb?
1 sb = 31415.92654 asb.
How do I convert stilbs to apostilbs?
Multiply the value in sb by 31415.92654. For example, 15 sb × 31415.92654 = 471238.898 asb.
Is the sb to asb conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "stilb".
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "apostilb".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Stilbs to Apostilbs (sb to asb). Retrieved October 25, 2026, from https://scientificconverters.com/luminance/stilbs-to-apostilbs/
IEEE
Scientific Converters, "Convert Stilbs to Apostilbs (sb to asb)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/luminance/stilbs-to-apostilbs/