Formula Guide

    How to Convert HEX, RGB & HSL Colors

    Colors on screens are defined by mixing red, green, and blue light. Web developers work with three representations of the same color: HEX (a 6-digit hexadecimal string like #FF5733), RGB (three integers 0–255), and HSL (hue in degrees, saturation and lightness as percentages). Being able to convert between them helps you understand design tools, CSS, and image editors.

    Last updated: March 31, 2026

    The Formula

    HEX to RGB: R = hex(1–2), G = hex(3–4), B = hex(5–6) each converted from hex to decimal
    RGB to HEX: convert each R, G, B value to 2-digit hex, concatenate with #
    RGB to HSL:
      R' = R/255, G' = G/255, B' = B/255
      Max = max(R',G',B'), Min = min(R',G',B'), Δ = Max−Min
      L = (Max + Min) / 2
      S = Δ / (1 − |2L − 1|)  (if L ≠ 0 or 1)
      H = 60 × ((G'−B')/Δ mod 6)  if Max=R'
    HSL is intuitive for design: Hue (0°–360°) is the color wheel position, Saturation (0–100%) is color intensity, Lightness (0–100%) ranges from black to white.

    Variable Definitions

    SymbolNameDescription
    R, G, BRed, Green, BlueEach channel is an integer 0–255. 0 = none of that color, 255 = full intensity.
    H, S, LHue, Saturation, LightnessHue: 0°=red, 120°=green, 240°=blue. Saturation: 0%=gray, 100%=vivid. Lightness: 0%=black, 50%=normal, 100%=white.

    Step-by-Step Example

    Convert the color #FF5733 to RGB, then find its approximate HSL values.

    Given

    HEX color:#FF5733

    Solution

    1. 1
      Split hex into pairs: FF = Red, 57 = Green, 33 = Blue
    2. 2
      Convert each pair from hex to decimal: FF = 255, 57 = 87, 33 = 51
    3. 3
      RGB result: rgb(255, 87, 51)
    4. 4
      Normalise: R'=255/255=1.0, G'=87/255=0.341, B'=51/255=0.2: Max=1.0(R), Min=0.2(B), Δ=0.8
    5. 5
      Lightness L = (1.0+0.2)/2: L = 0.6 = 60%
    6. 6
      Saturation S = 0.8/(1−|2×0.6−1|) = 0.8/0.8: S = 1.0 = 100%
    7. 7
      Hue H = 60 × ((0.341−0.2)/0.8 mod 6): H = 60 × 0.176 ≈ 10.6°

    #FF5733 = rgb(255, 87, 51) = hsl(11°, 100%, 60%) — a vivid orange-red.

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    Common Mistakes to Avoid

    Forgetting to divide R, G, B by 255 before the HSL calculation — the formula requires normalised values (0–1).

    Reading HEX pairs in the wrong order — always Red first, Green second, Blue third (#RRGGBB).

    Confusing HSL with HSV/HSB — Lightness 100% is white in HSL, but Value 100% is the pure hue in HSV (not white).

    Assuming #000000 is black — it is! But #FFFFFF is white. #808080 is mid-gray.

    Frequently Asked Questions

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