Hex Calculator · Practical guide
How to Add Hexadecimal Numbers
Hex addition works like decimal addition, except you carry at 16 — here's a step-by-step example.
At a glance
The short answer
Add hexadecimal numbers column by column from right to left, just like decimal, but a carry happens when a column reaches 16 instead of 10. Letters A-F stand for values 10-15. Worked example: 1A3F + 0B2 = 1AF1. Checking in decimal: 6719 + 178 = 6897, and 6897 in hex is 0x1AF1.
Interactive tool
Hex Calculator
Enter your own values, then compare the result with the examples below.
Result
Step-by-step: 1A3F + 0B2
- Align the numbers by the right edge: 1A3F over 0B2.
- Units column: F (15) + 2 = 17. Since 17 = 16 + 1, write 1 and carry 1.
- Sixteens column: 3 + B (11) + 1 (carry) = 15, which is F. No carry.
- 256s column: A (10) + 0 = A.
- 4096s column: 1.
- Result: 1AF1.
Quick reference for the letters
| Hex Digit | Decimal Value |
|---|---|
| A | 10 |
| B | 11 |
| C | 12 |
| D | 13 |
| E | 14 |
| F | 15 |
When a column overflows
Carrying in hex means subtracting 16 and adding 1 to the next column. For example, F + F = 15 + 15 = 30, and 30 = 16 + 14, so you write E and carry 1. If the topmost column carries, the result gains a digit: 0xFF + 0x01 = 0x100 (255 + 1 = 256). Enter both numbers in the calculator above to see the result in hex, decimal, and binary, along with the decimal steps used to verify it.
Frequently Asked Questions
What does 0x mean in front of a hex number?
The 0x prefix is a programming convention that marks the number as hexadecimal, so 0x10 means hex 10 (decimal 16), not ten. The calculator accepts input with or without the prefix.
Is hex addition case-sensitive?
No. The digits A-F and a-f mean the same thing. This calculator accepts either case and displays results in uppercase.
Why do programmers use hexadecimal?
Each hex digit maps to exactly four binary bits, so hex is a compact, readable shorthand for binary values like memory addresses, bytes, and color codes.
What is FF + FF in hex?
FF + FF equals 1FE in hex. In decimal that is 255 + 255 = 510, and 510 divided back into base 16 is 0x1FE.