Hex Signed Integer Calculator
Read a hex value as a signed integer type (int8, int16, int32, int64) — the same interpretation debuggers use for variables.
Full breakdown (input at 8-bit)
How Signed Integer Types Read Hex Bytes
A signed integer type doesn't change the bits in memory — it changes how they're interpreted. Pick the bit width matching the type (8, 16, 32, or 64), and the calculator checks the sign bit at that width: if it's set, the value is negative under two's complement; otherwise it reads as its plain positive value.
Where Signed Hex Values Actually Show Up
Debugging a Variable's Displayed Value
When a debugger or crash log shows a variable's raw hex bytes, matching the bit width and signedness to the variable's actual declared type is what tells you whether -10 or 246 is the real value.
0xF6 as int8 = -10
Reading a Signed Field in a Protocol
Network and file protocols that specify a field as "signed 16-bit" or "int32" need this exact check — reading the same bytes as unsigned would give a completely different, wrong number.
0x8000 as int16 = -32,768
Verifying a Sensor's Negative Reading
Temperature and accelerometer sensors often report signed values over a hex interface — this confirms a raw reading like 0xFF genuinely means -1, not 255.
0xFF as int8 = -1
Signed Integer Type Ranges
| Type | Bit width | Range |
|---|---|---|
| int8 | 8-bit | -128 to 127 |
| int16 | 16-bit | -32,768 to 32,767 |
| int32 | 32-bit | -2,147,483,648 to 2,147,483,647 |
| int64 | 64-bit | -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 |
Common Mistakes Reading Signed Integer Hex
- Picking the wrong bit width for the variable's actual declared type.
- Assuming a hex byte is always positive without checking the sign bit.
- Mixing up a signed type's range with its unsigned counterpart's range.
Why Use This Calculator Instead of Doing It by Hand
- Checks the sign bit and applies two's complement for you at any of the four common widths
- Runs entirely in your browser — nothing you type gets sent anywhere
- Lets you flip between int8/int16/int32/int64 instantly on the same value
- Shows decimal, binary, and octal alongside the signed result
Frequently Asked Questions
What does it mean to read a hex value as a signed integer?
It means interpreting the bit pattern using two's complement at a specific integer type's width — int8 (8-bit), int16, int32, or int64 — so the same bits can represent either a positive or negative number depending on the sign bit.
Why do debuggers show the same hex bytes as different numbers?
Because the variable's declared type determines both the bit width and whether it's signed — an int8 and a uint8 holding the identical bit pattern 0xFF display as -1 and 255 respectively.
What's the range of each signed integer type?
int8 is -128 to 127, int16 is -32,768 to 32,767, int32 is about -2.1 billion to 2.1 billion, and int64 covers an enormous range — each type's negative range is one wider than its positive range.
How is this different from just reading a hex value as decimal?
Plain hex-to-decimal always gives a non-negative number. This calculator additionally checks the sign bit for the chosen integer width and returns a negative result when that bit is set — matching how signed variables actually behave in code.
Which integer type should I pick if I'm not sure?
Match it to the variable's declared type in your code or the field width in your data format — int8/int16/int32/int64 in most C-family languages, or check your language's documentation if the naming differs.
Is this the same as the Hex to Negative Decimal converter?
The underlying math is identical — this page frames it around programming integer types (int8/int16/int32/int64) specifically, for anyone debugging typed variables rather than doing general arithmetic.
How do I convert hex to a signed integer in my head, fast?
Check if the first hex digit is 8 or higher at your type's top byte — if so, it's negative. For a quick estimate on int8, subtract 256 from the unsigned reading; 0xF6 unsigned is 246, minus 256 is -10.
What's a signed hex calculator actually checking for me?
It's checking the sign bit at your chosen width and applying two's complement if it's set — the same check your CPU and compiler do silently every time a signed variable's value gets read or printed.