Hex to C++ Integer Converter
Convert a hex value into a C++ integer literal — the same 0x syntax as C, with modern C++ options like fixed-width <cstdint> types.
Built by
Swapnil SanghviFull-Stack Web Developer & WordPress Developer
Swapnil Sanghvi is a full-stack web and WordPress developer, UI designer, and full-time freelancer who builds and maintains Hex Calculator.
Further reading: hex — Stack Overflow
How C++ Represents Hex Literals
C++ accepts a 0x-prefixed hex literal exactly like C does, including the same U/L/LL suffix rules for values that don't fit a plain int — see the Hex to C Integer calculator for a bit-width-aware version of those suffix rules.
Where Hex to C++ Integer Actually Comes Up
Defining a constexpr Constant
Pasting a hex value from a spec or design document into a constexpr declaration, so it's computed at compile time rather than runtime.
constexpr std::uint32_t COLOR = 0x2563EB;
Initializing a Fixed-Width Type From <cstdint>
Writing a hex literal for a std::uint8_t or std::int16_t variable, understanding that the literal itself is untyped until assigned or cast.
std::uint8_t flags = 0xFF;
Porting a C Constant Into C++ Code
Since C++'s hex literal syntax matches C's exactly, existing C hex constants can be copied into C++ source without modification.
#define MASK 0xFF -> constexpr auto MASK = 0xFF;
Why Use This Calculator Instead of Doing It by Hand
- Produces a syntactically valid C++ hex literal instantly
- Runs entirely in your browser — nothing you type gets sent anywhere
- Saves manually adding the 0x prefix and fixing letter case
- Pairs with the bit-width-aware Hex to C Integer calculator for suffix decisions
Limitations
- Doesn't add a suffix (U/L/LL) automatically — use the Hex to C Integer calculator's bit-width selector if you need a suggested suffix and type.
- Doesn't insert C++14 digit separators (like 0xDEAD'BEEF) — the output is a plain, ungrouped literal.
Frequently Asked Questions
Is C++'s hex literal syntax the same as C's?
Yes — C++ inherited C's 0x-prefixed hex literal syntax and suffix rules (U, L, UL, LL, ULL) exactly, including the same rule that a bare hex literal is never narrower than int.
What's the modern C++ way to specify an exact-width integer?
Use the fixed-width types from <cstdint> — std::uint8_t, std::int32_t, and so on — combined with a cast or brace-initialization, since C++ (like C) has no dedicated narrow-width literal syntax.
Can I use digit separators in a C++ hex literal?
Yes — C++14 added the single-quote digit separator, so 0xDEAD'BEEF is valid and equivalent to 0xDEADBEEF, useful for readability on longer constants.
Does constexpr change anything about hex literals?
No — constexpr affects when a value is computed (compile-time vs. runtime), not how the literal itself is written; a hex literal works identically whether or not it's used in a constexpr context.