Color Temperature Converter - Kelvin to RGB Color

How to use this tool

1. Enter a color temperature in Kelvin or its reciprocal mired value.
2. Read the approximate swatch, HEX, RGB, and converted mired result.
3. Optionally compare the current temperature with a target to estimate shift direction.
4. Copy the HEX, RGB, or CSS rgb() value for use in another tool.

What is color temperature?

Color temperature describes the visual warmth or coolness of a white-light source, measured in Kelvin (K). It is based on the color a theoretical "black body" radiator would glow at a given temperature.

Common values

• 1800 K: Candlelight: deep orange-red glow.
• 2700–3000 K: Warm white incandescent bulbs used in homes.
• 3200 K: Halogen / warm studio lighting.
• 5500–6000 K: Average noon sunlight, photographic daylight.
• 6500 K: Standard daylight white point (D65), used in monitors.
• 7500–10 000 K: Overcast sky to clear blue sky.

RGB approximation

The conversion uses Tanner Helland's algorithm, which provides a fast and visually accurate approximation from 1 000 K to 40 000 K. Values outside that range are clamped.

The formula estimates an RGB color from a blackbody temperature; it does not measure or reproduce the complete spectrum of a real bulb. Two LED fixtures labeled with the same Kelvin rating can render different colors because their spectral output differs. Treat the swatch as a useful visual reference for design, white-balance planning, or comparing lighting values, rather than a colorimeter reading. RGB and HEX values also depend on the display and color profile used to view them.

Mired values and white-balance shifts

Mired means micro reciprocal degrees. Convert Kelvin to mired with 1,000,000 ÷ K; convert back by dividing 1,000,000 by the mired value. Because this scale is reciprocal, a change of 100 K near a warm household bulb does not represent the same step as 100 K near daylight. Mired differences give photographers and lighting crews a more practical way to describe approximate warm or cool corrections.

For example, 3,200 K is about 312.5 mired, while 5,600 K is about 178.6 mired. Their difference is roughly 133.9 mired, indicating a shift toward cooler daylight. Enter either unit above to update the swatch, or open “Compare a white-balance shift” to compare the current source with a target such as tungsten, flash/daylight, or D65. Mired input is rounded to the nearest 100 K so it stays aligned with the converter's Kelvin controls.

The shift helper reports direction only: real lamps, camera sensors, and color-correction filters have spectral properties that a single Kelvin number cannot describe. Its CTO/CTB wording is a convenient approximation, not a recommendation for a specific gel or guaranteed match. Check manufacturer specifications and test the actual light when color consistency is important.

White balance in photography

White balance (WB) is a camera setting that adjusts the color of light so that whites appear white (not warm or cool) in the captured image. Without white balance correction, an indoor scene lit by tungsten bulbs (~2700 K) will appear orange if the camera is set for daylight (~5500 K), and a cloudy outdoor scene (~6500 K) will look bluish if no correction is applied. Modern cameras offer preset white balance modes (Daylight, Cloudy, Shade, Tungsten, Fluorescent) corresponding to common lighting temperatures, as well as a "Custom" or "Kelvin" mode where you set the exact temperature.

Circadian rhythm impact

Light color temperature affects the human body's production of melatonin, the sleep hormone:

• 5500 K and above (blue-white daylight): strongly suppresses melatonin production, promoting alertness. Ideal for workplaces, task lighting, and morning exposure. Screen use of bright blue-white light in the evening delays sleep onset.
• 2700–3000 K (warm white): low melatonin suppression. Better for bedrooms and evening environments. "Night mode" / "warm mode" on smartphones reduces blue-light emission by shifting toward this temperature range.

Monitor calibration standards

• D65 (6500 K): the standard white point for consumer monitors, sRGB, and web design. When calibrating a monitor for web work, aim for a white point of D65.
• D50 (5000 K): the standard white point for print work and prepress. Slightly warmer than D65 to simulate viewing printed output under a print-evaluation light source. Graphic designers working on print-destined content should calibrate their monitors to D50 and use a D50-illuminated light box when comparing screen to print.