Color Temperature Calculator
Our art & design fundamentals calculator teaches color temperature step by step. Perfect for students, teachers, and self-learners.
Formula
Mired = 1,000,000 / Kelvin | RGB derived from Planckian radiation curves
Color temperature in Kelvin is converted to RGB using approximation algorithms based on black body radiation physics. The Mired value is the micro reciprocal degree, calculated as one million divided by the Kelvin temperature, providing a perceptually uniform scale for comparing color temperature differences.
Worked Examples
Example 1: Matching Studio Lighting to Daylight
Problem: A photographer needs to match studio lights to midday sunlight (5500K). Calculate the RGB color, mired value, and identify what camera white balance preset to use.
Solution: Kelvin: 5500K\nRGB: approximately (255, 236, 224) - very slightly warm white\nMired: 1000000 / 5500 = 182 mireds\nClassification: Daylight\nClosest camera preset: Flash (5500K)\nThe slight warmth in RGB values reflects that even daylight is not perfectly neutral - it has a subtle warm cast compared to theoretical equal-energy white.
Result: 5500K = Daylight | Mired: 182 | Use Flash or Daylight white balance preset
Example 2: Choosing LED Bulbs for a Living Room
Problem: Select the right color temperature for a cozy living room atmosphere. Compare 2700K warm white versus 4000K neutral white in terms of RGB appearance and mood.
Solution: 2700K Warm White: RGB approximately (255, 180, 107)\nClassification: Warm White\nMired: 370\nMood: Relaxing, intimate, cozy\n\n4000K Neutral White: RGB approximately (255, 209, 163)\nClassification: Neutral White\nMired: 250\nMood: Clean, balanced, functional\n\nDifference: 120 mireds = significant visual shift
Result: 2700K for cozy ambiance | 4000K for functional spaces | 120 mired difference
Frequently Asked Questions
What is color temperature in lighting and photography?
Color temperature is a measurement in Kelvin (K) that describes the color appearance of light emitted by a source, based on the concept of a theoretical black body radiator heated to various temperatures. Lower Kelvin values (2000-3000K) produce warm, reddish-orange light similar to candlelight or incandescent bulbs. Higher values (5000-6500K) produce cool, bluish-white light similar to daylight. This measurement is fundamental to photography, cinematography, lighting design, and display calibration. Understanding color temperature helps photographers set accurate white balance, lighting designers create appropriate atmospheres, and display manufacturers calibrate monitors for accurate color reproduction.
How does color temperature affect photography white balance?
White balance in photography adjusts the camera sensor interpretation to make white objects appear truly white under different lighting conditions. When you set your camera white balance to match the ambient color temperature, the camera applies an opposite color shift to neutralize the light color cast. If the ambient light is 3200K (warm tungsten), setting white balance to 3200K adds blue to compensate. If ambient light is 7000K (cool shade), setting to 7000K adds warmth. Creative photographers deliberately mismatch white balance to create mood effects, such as setting a warm white balance during blue hour for exaggerated golden tones. Most digital cameras offer preset white balance modes and manual Kelvin adjustment.
What are common color temperatures for different light sources?
Candle flame produces approximately 1800-2000K with a deep amber glow. Standard incandescent bulbs emit 2700K warm white light. Halogen bulbs produce 3000-3200K slightly whiter light. Cool white fluorescent tubes operate at 4000-4500K. Direct midday sunlight is approximately 5200-5500K. Electronic flash units produce 5500-6000K daylight-balanced light. Overcast skies range from 6000-7000K with a subtle blue cast. Open shade under a blue sky can reach 7500-9000K with a pronounced blue tint. Clear north sky can exceed 10000K. Modern LED bulbs are available across the entire spectrum from 2200K to 6500K, making them extremely versatile for both residential and commercial applications.
How does color temperature affect mood and interior design?
Color temperature profoundly influences psychological responses and spatial perception in interior environments. Warm light (2700-3000K) creates feelings of relaxation, comfort, and intimacy, making it ideal for bedrooms, living rooms, restaurants, and hospitality spaces. Neutral white light (3500-4000K) balances warmth and clarity, working well in kitchens, bathrooms, and retail environments. Cool white light (5000-6500K) promotes alertness, concentration, and productivity, making it appropriate for offices, hospitals, and task-oriented spaces. Research shows that warmer color temperatures lower blood pressure and heart rate, while cooler temperatures improve cognitive performance and reduce drowsiness.
What is CRI and how does it relate to color temperature?
CRI (Color Rendering Index) measures how accurately a light source reveals the true colors of objects compared to a reference illuminant, on a scale from 0 to 100. CRI is independent of color temperature but the reference illuminant changes based on temperature. For sources below 5000K, an incandescent black body radiator is the reference. Above 5000K, a phase of CIE standard illuminant D (daylight) is used. A high CRI (90 or above) means colors appear natural and vivid under that light. Low CRI sources like sodium vapor street lights (CRI around 25) make everything appear yellowish-brown. For photography, retail, and art galleries, CRI of 95 or above is recommended to ensure accurate color perception.
How do I convert Kelvin temperature to RGB values?
Converting Kelvin to RGB uses approximation algorithms because the relationship is based on Planck radiation curves rather than simple linear equations. The most widely used algorithm was developed by Tanner Helland and operates in three stages. For temperatures below 6600K, red is always 255 and blue is calculated logarithmically. For temperatures above 6600K, red decreases as a power function and blue is always 255. Green follows a logarithmic curve below 6600K and a different power curve above. This algorithm produces visually accurate results for the range of 1000K to 40000K. Professional implementations may use lookup tables derived from CIE data for higher precision in color-critical applications.