Every color you see on a screen, from a website's brand blue to a single emoji, is stored as numbers. HEX and RGB are simply two different ways of writing down the same numbers. This guide shows you exactly how to convert hex to RGB by hand, why the base-16 math behind it works the way it does, and where you can convert hex code to RGB instantly if you'd rather skip the arithmetic.

What HEX and RGB Actually Represent

Before converting anything, it helps to know what the two formats encode. Both HEX and RGB describe the same thing: how much red, green, and blue light a pixel emits. Screens are additive light sources, so mixing red, green, and blue light at different intensities produces every color you see — from #000000 (no light, black) to #FFFFFF (full red, green, and blue light, white).

RGB: three numbers, 0–255 each

RGB stands for Red, Green, Blue. Each channel is stored as an 8-bit number, meaning it can hold 256 possible values, from 0 (no light) to 255 (maximum light). A color is written as rgb(red, green, blue), for example rgb(46, 204, 113) for a shade of emerald green.

HEX: the same three numbers, written in base 16

A hex color code is a six-character string, such as #2ECC71, prefixed with a #. It's split into three two-character pairs — one each for red, green, and blue — but each pair is written in hexadecimal (base 16) instead of decimal (base 10). Hexadecimal uses sixteen symbols: 0–9 for zero through nine, and A–F for ten through fifteen.

The HEX to RGB Conversion Formula

Every hex color code follows the same structure: #RRGGBB, where RR, GG, and BB are two-digit hexadecimal numbers for red, green, and blue. To convert each pair to its decimal (0–255) equivalent, use this formula:

Each hex digit has a fixed decimal value:

• 0–9 → 0 through 9 (same as decimal)
• A → 10, B → 11, C → 12, D → 13, E → 14, F → 15

So for a pair like “2E”: the first digit “2” is worth 2, and the second digit “E” is worth 14. Plug those into the formula: (2 × 16) + 14 = 32 + 14 = 46. That's the red — or green, or blue — value for that pair.

Step-by-Step: Converting a HEX Code to RGB by Hand

1. Remove the # symbol. #2ECC71 becomes 2ECC71.
2. Split the six characters into three pairs: 2E, CC, 71.
3. Convert the first pair (red): 2E → (2 × 16) + 14 = 46.
4. Convert the second pair (green): CC → (12 × 16) + 12 = 204.
5. Convert the third pair (blue): 71 → (7 × 16) + 1 = 113.
6. Write the result as RGB: rgb(46, 204, 113).

That's the entire process — it's arithmetic, not approximation, which is why the two formats are always perfectly interchangeable for a standard 6-digit hex code.

Try It Yourself: Live HEX → RGB Converter

Worked Examples with Color Swatches

Here are five more hex codes converted to RGB, so you can check your own math against real results and see the actual colors side by side.

Why the Formula Works: The Math Behind Hexadecimal

Hexadecimal is a positional number system, just like the decimal system you use every day — it just counts in groups of 16 instead of groups of 10. In decimal, the two-digit number “46” means (4 × 10) + 6. In hexadecimal, the two-digit number “2E” means (2 × 16) + 14, because each position represents a power of 16 rather than a power of 10.

This is exactly why the conversion formula works: a two-digit hex pair can express any value from 0 (“00”) to 255 (“FF”), and 0–255 happens to be the exact range of an 8-bit color channel. Computers store color data in binary and bytes, and hexadecimal was adopted as a human-friendly shorthand for binary because each hex digit maps neatly onto exactly four binary bits (2⁴ = 16). Two hex digits therefore represent one full byte — one color channel — with no rounding or loss.

Does Converting HEX to RGB Lose Accuracy?

No — for a standard 6-digit hex code, converting to RGB and back is completely lossless. Both formats store the same 24-bit number (8 bits per channel); hex just writes it in base 16 and RGB writes it in base 10. Where accuracy questions do come up:

• 3-digit shorthand hex (like #2E7) expands each digit by doubling it (2→22, E→EE, 7→77), so it can only represent 4,096 of the 16.7 million colors a 6-digit hex code can — it's a real limitation, not a rounding error.
• HSL and HSV conversions involve trigonometric-style calculations that are often rounded to whole numbers for display, which can shift a color by a barely perceptible amount — try the HEX to HSL converter to see the exact values for any color.
• 8-digit hex codes (#RRGGBBAA) add an alpha/transparency channel — converting only the color portion is still lossless, but forgetting the alpha pair will change how the color renders against a background.

HEX, RGB, and HSL Quick-Reference Table

Use this table as a quick cross-reference between the three formats for a handful of common colors. If you need to go the other direction, the HEX to HSL tool converts any code you paste in.

Convert HEX to RGB Instantly with a Free Online Tool

Manual conversion is useful to understand, but for day-to-day design and development work, an online hex to RGB converter online free tool is faster and eliminates arithmetic mistakes.

A Note on Color Accessibility

Once you know a color's RGB values, you can also check whether it's accessible when paired with text or a background. The W3C's WCAG 2.1 guidelines define a color's relative luminance using the linearized, gamma-corrected RGB values, weighted by how sensitive the human eye is to each channel — roughly 21% for red, 72% for green, and only 7% for blue, since the eye is most sensitive to green light. That luminance value is then used to calculate a contrast ratio between two colors, which should be at least 4.5:1 for normal body text under WCAG AA. Converting your brand colors from hex to RGB is often the first step toward running that kind of accessibility check.

Frequently Asked Questions