Convert luminance units, calculate LED performance, and analyze lighting specifications with precision and ease
Convert multiple values at once. Enter one value per line:
Convert between luminous intensity (candela) and luminous flux (lumen) for individual LEDs
Process multiple LED values with the same beam angle:
Convert multiple values at once. Enter one value per line:
Convert between luminous intensity (candela) and luminous flux (lumen) for individual LEDs
Process multiple LED values with the same beam angle:
Our comprehensive lighting calculator combines luminance conversion and LED performance analysis in one professional platform. Whether you're calibrating displays, designing LED systems, or analyzing lighting specifications, our dual-calculator system provides the tools you need:
Professional lighting involves multiple measurement systems depending on the application:
| Unit | Symbol | Conversion to cd/m² | Common Use |
|---|---|---|---|
| Candela per square meter | cd/m² | 1.0000 | SI standard unit |
| Nit | nt | 1.0000 | Display technology |
| Foot-lambert | fL | 3.4263 | US cinema industry |
| Stilb | sb | 10,000 | CGS system |
| Lambert | L | 3,183.1 | Older photometry |
| Apostilb | asb | 0.3183 | European standard |
| Candela per square centimeter | cd/cm² | 10,000 | Small area measurements |
| Candela per square foot | cd/ft² | 10.764 | US lighting industry |
| Candela per square inch | cd/in² | 1,550 | Small displays |
| Kilocandela per square meter | kcd/m² | 1,000 | High-brightness applications |
| Millinit | mnt | 0.001 | Very dim displays |
LED calculations require understanding the relationship between intensity and total output:
Our luminance converter uses scientifically established conversion factors based on the International System of Units (SI). The base unit for luminance is the candela per square meter (cd/m²), which is defined by the International Bureau of Weights and Measures (BIPM).
The conversion formulas used in our calculator are:
LED conversions between candela and lumen require beam angle considerations using solid angle mathematics:
Core Formula: Φ = I × Ω
Solid Angle Calculation: Ω = 2π(1 - cos(θ/2))
These conversion factors are derived from internationally recognized standards established by the Commission Internationale de l'Éclairage (CIE) and the International Bureau of Weights and Measures. The relationships between these units are mathematically exact, ensuring consistent and accurate conversions across all applications.
Our calculator uses conversion factors with four decimal places of precision, which exceeds the accuracy requirements for most practical applications in display technology, lighting design, and photometric measurements. The batch conversion feature maintains this precision across multiple values simultaneously, making it suitable for professional calibration workflows and research applications.
Our enhanced safety warning system automatically alerts users to potentially harmful luminance levels (>10,000 cd/m²), while the visual brightness scale provides immediate context by showing where any measurement falls on the spectrum from starlight to bright sunlight.
This converter is based on internationally recognized standards and established scientific principles. All conversion factors have been verified against multiple authoritative sources, including CIE standards and NIST guidelines. The calculations use established mathematical relationships that have been validated in scientific literature and are widely accepted in the photometry field.
Understanding both luminance and LED performance is crucial across multiple industries. Display engineers use luminance measurements (cd/m²) for screen calibration while also needing LED backlight specifications (candela/lumen). Lighting designers work with surface brightness for architectural applications and individual LED performance for fixture design. The cinema industry uses foot-lamberts for screen brightness while LED cinema projectors require candela-lumen calculations for lamp specifications.
Our unified calculator suite eliminates the need for multiple tools, providing professional-grade accuracy with beginner-friendly explanations and advanced batch processing capabilities for efficiency in professional workflows.
Luminance measures the brightness of surfaces (like displays, screens, or illuminated panels) in units like cd/m² or nits. LED performance calculations deal with individual LED characteristics, converting between luminous intensity (candela) and total light output (lumen) using beam angle considerations. Our calculator suite handles both applications.
The conversion uses the formula: Lumens = Candela × Solid Angle, where the solid angle depends on the LED's beam angle. The solid angle formula is 2π(1 - cos(beam_angle/2)). Our LED calculator automatically handles this complex calculation when you input the beam angle in degrees.
Luminance measures the luminous intensity per unit area of light traveling in a given direction. It's crucial for display calibration, lighting design, vision research, and ensuring proper illumination levels in various environments. Unlike illuminance, which measures light falling on a surface, luminance measures light emitted or reflected from a surface toward the observer.
Candela per square meter (cd/m²) and nit are exactly the same unit. "Nit" is simply a more convenient name for cd/m² commonly used in display technology and consumer electronics. The term "nit" comes from the Latin word "nitere," meaning "to shine."
Beam angle determines how the LED's light is distributed in space. A narrow beam concentrates light in a small area (higher intensity per direction), while a wide beam spreads light over a larger area (lower intensity per direction but same total output). This affects the candela-to-lumen conversion ratio significantly.
The cinema industry, particularly in the United States, has historically used foot-lamberts (fL) as the standard unit for screen luminance measurement. This tradition dates back to early film projection standards. Cinema screens are typically calibrated to 14 fL, which equals approximately 48 cd/m².
Millicandela (mcd) is 1/1000th of a candela (cd). Many LEDs, especially indicator LEDs, are rated in millicandela because their intensity is relatively low. High-power LEDs for lighting applications are typically rated in candela. Our calculator handles both units seamlessly.
Our conversion factors are based on internationally recognized standards and are accurate to four decimal places. For LED calculations, we use the exact mathematical relationship between solid angles and beam angles. This precision level is sufficient for most practical applications in both display technology and LED design.
Safe luminance levels depend on viewing duration and conditions. For prolonged computer use, monitors should typically be set between 100-200 cd/m². Direct viewing of sources above 10,000 cd/m² can cause discomfort or eye damage. Always follow manufacturer guidelines and occupational safety standards for your specific application.
Yes, our calculator suite handles HDR (High Dynamic Range) displays and high-performance LEDs. HDR displays can produce luminance levels from 0.01 to 10,000 cd/m² or higher, while high-power LEDs can exceed 1000 candela. The converter handles these wide ranges accurately, with automatic performance categorization and safety warnings.
Luminance is an objective physical measurement, while brightness is subjective human perception. The relationship is non-linear due to how human vision adapts to different light levels. Doubling the luminance doesn't necessarily double the perceived brightness. Understanding this distinction is important when designing displays and lighting systems.
All conversion calculations are based on internationally recognized standards (CIE, BIPM, NIST) and are accurate to four decimal places for most practical applications. However, we make no warranties regarding absolute accuracy for all use cases.
While our calculator is designed for professional use, it should supplement, not replace, professional engineering judgment. For critical applications, please verify results with certified measurement equipment and consult qualified professionals.
Safety warnings are provided as general guidance. Actual safety requirements depend on specific applications, viewing conditions, and regulatory standards. Always follow applicable safety regulations and manufacturer guidelines.
All calculations are performed entirely in your browser (client-side). No input data, results, or personal information is collected, stored, or transmitted to our servers, ensuring complete privacy of your calculations.
This tool is provided for educational and informational purposes. While we strive for accuracy, users should verify critical calculations independently. The calculator should not be the sole basis for decisions in professional or safety-critical applications.
We regularly update our calculator based on user feedback and evolving standards. If you notice any discrepancies or have suggestions for improvement, please contact us through our feedback channels.