Conversion method
Luminous intensity is luminous flux per solid angle. Historical candle definitions vary; candela prefixes are unambiguous.
mcd = x × 1000
10 cd = 10000 mcd.
| cd | mcd |
|---|---|
| 1 | 1000 |
| 5 | 5000 |
| 10 | 10000 |
| 25 | 25000 |
| 50 | 50000 |
| 100 | 100000 |
Unit definitions and sources
Luminous intensity is luminous flux per solid angle. Historical candle definitions vary; candela prefixes are unambiguous.
| Unit and system | Use | Definition | Relationship |
|---|---|---|---|
| Candela (cd); si | Common units | Candela: base (cd) = value × 1. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Millicandela (mcd); si | Common units | Millicandela: base (cd) = value × 0.001. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Kilocandela (kcd); si | Specialist units | Kilocandela: base (cd) = value × 1000. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Microcandela (µcd); si | Specialist units | Microcandela: base (cd) = value × 1e-06. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Exacandela (Ecd); si | Specialist units | exacandela: E denotes 10^18; the unit gives 1000000000000000000 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Petacandela (Pcd); si | Specialist units | petacandela: P denotes 10^15; the unit gives 1000000000000000 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Teracandela (Tcd); si | Specialist units | teracandela: T denotes 10^12; the unit gives 1000000000000 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Gigacandela (Gcd); si | Specialist units | gigacandela: G denotes 10^9; the unit gives 1000000000 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Megacandela (Mcd); si | Specialist units | megacandela: M denotes 10^6; the unit gives 1000000 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Hectocandela (hcd); si | Specialist units | hectocandela: h denotes 10^2; the unit gives 100 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Decacandela (dacd); si | Specialist units | decacandela: da denotes 10^1; the unit gives 10 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Decicandela (dcd); si | Specialist units | decicandela: d denotes 10^-1; the unit gives 0.1 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Centicandela (ccd); si | Specialist units | centicandela: c denotes 10^-2; the unit gives 0.01 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Nanocandela (ncd); si | Specialist units | nanocandela: n denotes 10^-9; the unit gives 1e-9 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Picocandela (pcd); si | Specialist units | picocandela: p denotes 10^-12; the unit gives 1e-12 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Femtocandela (fcd); si | Specialist units | femtocandela: f denotes 10^-15; the unit gives 1e-15 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
| Attocandela (acd); si | Specialist units | attocandela: a denotes 10^-18; the unit gives 1e-18 cd. Common use: Luminous Intensity. Source checked 2026-09-20 (implementation review). | Exact definition; numerical display may be rounded |
Sources: NIST: SP 811 Appendix B.8: conversion factors; BIPM: SI prefixes
Precision of luminous intensity conversions
All 17 luminous intensity units convert through Candela (cd). 17 have an exact defined relationship to the base unit and 0 are conventional or measured values. Results and the tables on this page come from the same engine, so a table value can be checked against the converter directly.
Standard display shows up to six decimal places, switching to scientific notation for very large or small values. Calculation uses JavaScript binary floating point independently of display rounding, so extra digits are not a claim about measurement accuracy. Each unit lists its own source; a citation records where the definition comes from, not an independent review. See Conversion methodology for the review and correction process.