What is hexadecimal, and why do computers use it?

Hexadecimal is a base-16 number system using 16 symbols: 0–9 and A–F, where A=10 through F=15. Computers use hex because each hex digit represents exactly 4 binary bits, making it compact and human-readable. It is widely used in memory addresses, HTML color codes, error codes, and network MAC addresses.

How do you convert hexadecimal to decimal?

Multiply each hex digit by 16 raised to its position, starting from position 0 on the right. Replace letters A–F with 10–15. Then add all the results together. For example, 3B = 3×16 + 11×1 = 48 + 11 = 59.

What is the formula for hex to decimal conversion?

The formula is: Decimal = d(n-1) × 16^(n-1) + ... + d1 × 16^1 + d0 × 16^0. Each digit is multiplied by 16 raised to its positional index, and the results are summed.

How do I convert a hex color code to decimal?

Split the hex color code into three pairs. Each pair represents a Red, Green, or Blue channel. Convert each pair separately. For example, #FF5733: FF=255 (Red), 57=87 (Green), 33=51 (Blue), giving rgb(255, 87, 51).

Why is hexadecimal used in computing instead of binary?

Binary is what computers use internally, but it is hard for humans to read. Hex is more compact — one hex digit represents exactly 4 binary bits. So 11111111 in binary becomes just FF in hex. Hex aligns perfectly with bytes (8 bits = 2 hex digits), making it easier to read memory addresses, color values, and error codes.

What are common mistakes when converting hex to decimal?

The three most common mistakes are: 1) Forgetting to replace hex letters A–F with their decimal values (10–15). 2) Getting position values backwards — position 0 starts at the rightmost digit. 3) Adding before multiplying — always multiply each digit by its power of 16 first, then add the results.

Can I convert hex to decimal in Python, JavaScript, or other programming languages?

Yes. In Python, use int('1A3', 16) which returns 419. In JavaScript, use parseInt('1A3', 16) which returns 419. In C++, use std::stoi('1A3', nullptr, 16). In Java, use Integer.parseInt('1A3', 16). All these specify base 16 as the radix parameter.

Hexadecimal to Decimal Converter

Q: What is FF in decimal?

FF in hexadecimal equals 255 in decimal. Calculated as: 15×16 + 15×1 = 240 + 15 = 255. FFFF in hexadecimal equals 65,535 in decimal, which is the maximum value of a 16-bit unsigned integer.

Q: How do I convert decimal to hexadecimal?

Use repeated division by 16. Divide the decimal number by 16 and note the remainder. Repeat until the quotient is 0. Read the remainders from bottom to top — that is your hex number. For example, 255 ÷ 16 = 15 remainder 15 (F), then 15 ÷ 16 = 0 remainder 15 (F). Reading upward gives FF.

Q: What is signed 2's complement in hex conversion?

Signed 2's complement is how computers represent negative integers. In a signed 8-bit system, FF does not equal 255 — it equals -1. To convert, check if the leftmost bit is 1 (negative), flip all bits, add 1, convert to decimal, then add a minus sign. Our converter shows both unsigned and signed values automatically.

This free hex to decimal converter handles everything instantly. It works for short codes like FF and long integers up to 16 hex characters. It even shows the binary equivalent and signed 2's complement.

Whether you're a developer, student, or just solving a quick problem, this tool is built for you.

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Enter hex number

Decimal result

Decimal number

Decimal from signed 2's complement

Binary number

Digit grouping

Hex to decimal calculation steps

How to Calculate Hexadecimal to Decimal

Type a hex value below — or use the converter above — and watch the step-by-step breakdown animate in real time.

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Enter a hexadecimal number above to see the visual calculation

How to Use This Hex to Decimal Calculator

It takes three steps. That's it.

Type your hex value into the input box.

Hit the Convert button.

Read your decimal result instantly.

You can also convert decimal back to hex. Just switch the input direction and hit convert again. The tool handles both directions with zero effort.

Need to start over? Hit Reset and the fields clear immediately.

What Is Hexadecimal? (And Why Do We Use It?)

Hexadecimal is a base-16 number system. It uses 16 unique symbols to represent values.

Those symbols are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F.

The letters A through F replace the numbers 10 through 15. Each position in a hex number represents a power of 16.

Where Is Hex Used in Real Life?

You've seen hex more than you think. Here are the most common places:

HTML color codes — #FF5733 is a hex code for a bold orange-red color.
Memory addresses — Computers store memory locations in hex format.
RGB values — Web designers use hex to define precise colors.
Programming — Languages like C, Python, and JavaScript use hex constants.
Error codes — System error messages often use hexadecimal identifiers.

Hex is compact. It represents large binary values in fewer characters. That's why computers love it and programmers rely on it daily.

What Is the Decimal System?

Decimal is a base-10 number system. It's the system humans use every day.

It uses 10 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

Each digit position represents a power of 10. So the number 253 means:

2 × 10² + 5 × 10¹ + 3 × 10⁰ = 200 + 50 + 3 = 253

Decimal is called "base 10" because of those 10 symbols. Computers use other bases like binary (base 2) and hex (base 16). But humans always end up converting back to decimal to understand a value.

That's exactly why a hexadecimal to decimal converter is so useful.

How to Convert Hexadecimal to Decimal by Hand

You can do this manually with a simple formula.

The Formula

Decimal = d_n-1 × 16^n-1 + ... + d₁ × 16¹ + d₀ × 16⁰

Each digit in the hex number gets multiplied by 16 raised to its position. Then you add all the results together.

Hex to Decimal Conversion: Step-by-Step

Here's the process broken down clearly:

Write out each digit of the hex number from right to left.
Assign a position starting at 0 (rightmost = position 0).
Multiply each digit by 16 raised to its position number.
Add all the results together.

That final sum is your decimal number.

Hex to Decimal Conversion Examples

Let's walk through real examples so the method clicks.

Example 1: Convert 3B (hex) to Decimal

3B₁₆ = 3 × 16¹ + 11 × 16⁰ = 3 × 16 + 11 × 1 = 48 + 11 = 59

Example 2: Convert 7DE (hex) to Decimal

7DE₁₆ = 7 × 16² + 13 × 16¹ + 14 × 16⁰ = 7 × 256 + 13 × 16 + 14 × 1 = 1792 + 208 + 14 = 2014

Example 3: Convert E7A9 (hex) to Decimal

E7A9₁₆ = 14 × 16³ + 7 × 16² + 10 × 16¹ + 9 × 16⁰ = 57344 + 1792 + 160 + 9 = 59305

Example 4: Convert FF (hex) to Decimal

FF₁₆ = 15 × 16¹ + 15 × 16⁰ = 240 + 15 = 255

FF is the most common hex value. It shows up in color codes, network masks, and bit flags constantly.

Example 5: Convert 1A (hex) to Decimal

1A₁₆ = 1 × 16¹ + 10 × 16⁰ = 16 + 10 = 26

Don't want to do the math yourself? Use the hex to decimal calculator at the top of this page. It's instant and handles values up to 16 hex characters.

How to Convert Decimal to Hexadecimal

Need to go the other direction? Converting decimal to hex is just as simple.

The Method

Divide the decimal number by 16.
Note the remainder. That's your least significant hex digit.
Divide the quotient by 16 again.
Repeat until the quotient is 0.
Read the remainders from bottom to top. That's your hex number.

Example: Convert 255 (Decimal) to Hexadecimal

255 ÷ 16 = 15 remainder 15 → F

15 ÷ 16 = 0 remainder 15 → F

Read remainders upward: FF

So 255₁₀ = FF₁₆. That's why #FFFFFF means pure white in HTML.

Example: Convert 4302 (Decimal) to Hexadecimal

4302 ÷ 16 = 268 remainder 14 → E

268 ÷ 16 = 16 remainder 12 → C

16 ÷ 16 = 1 remainder 0 → 0

1 ÷ 16 = 0 remainder 1 → 1

Read upward: 10CE

So 4302₁₀ = 10CE₁₆.

Use our decimal to hexadecimal converter to skip the manual steps entirely.

Hex to Decimal Conversion Table (Quick Reference)

Bookmark this table. It covers the most common hex values you'll encounter.

Hex (Base 16)	Decimal (Base 10)	Calculation
0	0	—
1	1	—
2	2	—
3	3	—
4	4	—
5	5	—
6	6	—
7	7	—
8	8	—
9	9	—
A	10	—
B	11	—
C	12	—
D	13	—
E	14	—
F	15	—
10	16	1×16¹ + 0×16⁰
1A	26	1×16¹ + 10×16⁰
1F	31	1×16¹ + 15×16⁰
20	32	2×16¹ + 0×16⁰
3B	59	3×16¹ + 11×16⁰
40	64	4×16¹ + 0×16⁰
64	100	6×16¹ + 4×16⁰
7F	127	7×16¹ + 15×16⁰
80	128	8×16¹ + 0×16⁰
A0	160	10×16¹ + 0×16⁰
C0	192	12×16¹ + 0×16⁰
FF	255	15×16¹ + 15×16⁰
100	256	1×16² + 0×16¹ + 0×16⁰
1D9	473	1×16² + 13×16¹ + 9×16⁰
200	512	2×16² + 0 + 0
3FF	1023	3×16² + 15×16¹ + 15×16⁰
400	1024	4×16² + 0 + 0
7DE	2014	7×16² + 13×16¹ + 14×16⁰
FFF	4095	15×16² + 15×16¹ + 15×16⁰
FFFF	65535	15×16³ + 15×16² + 15×16¹ + 15×16⁰

Need a value not listed here? Use the hex calculator tool at the top of this page for an instant result.

Why Developers and Students Love This Hex Converter

This isn't just another calculator. It's built for people who need answers fast.

Here's what makes it stand out:

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Instant Results

Type your hex code and get the decimal output in milliseconds. No delays. No loading screens.

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Two-Way Conversion

Convert hex to decimal or decimal to hex. Switch directions anytime. One tool does both.

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Extra Outputs Included

See the binary equivalent and signed 2's complement alongside your decimal result. All in one place.

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Works on Every Device

Use it on your laptop, tablet, or phone. The layout adjusts automatically for any screen size.

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Completely Free

No account needed. No paywalls. No limits on how many conversions you run.

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Accurate Every Time

The tool handles up to 16 hex characters without errors. Reliable math you can trust.

Frequently Asked Questions About Hex to Decimal Conversion

What is hexadecimal to decimal conversion? +

It's the process of changing a base-16 hex number into a base-10 decimal number. You multiply each hex digit by 16 raised to its position. Then you sum all the results. Our converter does this automatically in one click.

How do I convert hex to decimal manually? +

Write each digit's position starting from 0 on the right. Multiply each digit by 16 raised to its position. Add all results together. That sum is your decimal number. For example: 1E₁₆ = 1×16 + 14×1 = 30₁₀.

What is FF in decimal? +

FF in hex equals 255 in decimal. This is because F = 15, so FF = 15×16 + 15×1 = 240 + 15 = 255. This value appears often in color codes and binary masks.

What is the hex code to decimal for #FFFFFF? +

FFFFFF₁₆ = 16,777,215₁₀. This is the decimal value of pure white in RGB color space. Each pair (FF, FF, FF) equals 255 in red, green, and blue channels.

How do I convert decimal to hexadecimal? +

Divide the decimal number by 16 repeatedly. Note each remainder. When the quotient reaches 0, read the remainders from last to first. That sequence is your hex number. Use our decimal to hex converter to skip the manual steps.

What is a hex calculator used for? +

A hex calculator performs arithmetic using base-16 numbers. Developers use it for bitwise operations, memory address calculations, and color code conversions. Our hex to decimal tool handles direct number conversion instantly.

What is signed 2's complement in hex conversion? +

Signed 2's complement is a method computers use to represent negative integers. When converting a hex value, this tool shows both the unsigned decimal and the signed 2's complement interpretation. It's useful for low-level programming and embedded systems work.

How many hex digits equal one decimal digit? +

There's no fixed one-to-one relationship. A single hex digit (0–F) represents values 0–15, which needs up to 2 decimal digits. Larger hex numbers need proportionally more decimal digits to represent the same value. Our converter handles this automatically up to 16 hex digits.

Can I convert hex color codes to decimal? +

Yes. Enter any hex color value without the # symbol. For example, type FF5733 and convert each two-digit pair separately. FF = 255, 57 = 87, 33 = 51. Those are the R, G, and B values in decimal.

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