---
title: 1.28 Basic Numeric Limits
description: "C provides limits for integer and floating-point types through standard headers. Integer limits are available through ``, while floating-point limits are provided by ``. ``` #include #include #include int main() { printf(\"INT_MAX = %d\\n\", INT_MAX); printf(\"UINT_MAX = %u\\n\", UINT_MAX); printf(\"FLT_MAX…"
url: "https://edcret.in/docs/c-programming/basic-refreshers/1-28-basic-numeric-limits/"
updated: "2026-09-06"
category: C Programming / Basic Refreshers
---

# 1.28 Basic Numeric Limits

C provides limits for integer and floating-point types through standard headers. Integer limits are available through `<limits.h>`, while floating-point limits are provided by `<float.h>`.

```
#include <stdio.h>
#include <limits.h>
#include <float.h>

int main()
{
    printf("INT_MAX     = %d\n", INT_MAX);
    printf("UINT_MAX    = %u\n", UINT_MAX);

    printf("FLT_MAX     = %e\n", FLT_MAX);
    printf("DBL_MAX     = %e\n", DBL_MAX);

    printf("FLT_MIN     = %e\n", FLT_MIN);
    printf("DBL_MIN     = %e\n", DBL_MIN);

    return 0;
}
```

### Example Output

A typical implementation may produce:

```
INT_MAX     = 2147483647
UINT_MAX    = 4294967295
FLT_MAX     = 3.402823e+38
DBL_MAX     = 1.797693e+308
FLT_MIN     = 1.175494e-38
DBL_MIN     = 2.225074e-308
```

### Explanation

`<limits.h>` provides limits for integer types:

```
INT_MAX
UINT_MAX
```

`<float.h>` provides characteristics and limits for floating-point types:

```
FLT_MAX
DBL_MAX
FLT_MIN
DBL_MIN
```

Here, `FLT_MIN` and `DBL_MIN` represent the smallest **positive normalized** values, not the most negative values.

| Macro | Meaning |
| --- | --- |
| `FLT_MIN` | Smallest positive normalized `float` |
| `FLT_MAX` | Largest finite `float` |
| `DBL_MIN` | Smallest positive normalized `double` |
| `DBL_MAX` | Largest finite `double` |
| `LDBL_MIN` | Smallest positive normalized `long double` |
| `LDBL_MAX` | Largest finite `long double` |

Floating-point characteristics also include precision-related macros such as:

| Macro | Meaning |
| --- | --- |
| `FLT_DIG` | Decimal digits of precision for `float` |
| `DBL_DIG` | Decimal digits of precision for `double` |
| `LDBL_DIG` | Decimal digits of precision for `long double` |
| `FLT_EPSILON` | Difference between `1.0` and the next representable `float` |
| `DBL_EPSILON` | Difference between `1.0` and the next representable `double` |
| `LDBL_EPSILON` | Difference between `1.0L` and the next representable `long double` |

The exact values depend on the implementation. Using these macros is preferable to assuming a particular floating-point representation or range.