`float`

The built-in float data type represents floating-point numbers, which are numbers with a decimal point. You can create floats using literals, the float() constructor, or by converting strings or other numeric types:

>>> 1.5
1.5
>>> float("3.14")
3.14

float Constructors

float(number=0.0, /)
float(string, /)

Arguments

Argument	Description
`number`	A numeric value (integer or float) that will be converted to a float.
`string`	A string representing a float. This is a required argument.

Return Value

Returns a Python float object

float Examples

Creating a zero instance of a float:

>>> float()
0.0

Creating floats using literals, including scientific notation:

>>> 3.14
3.14
>>> -0.5
-0.5
>>> 1e-3
0.001

Creating floats using the class constructor:

>>> float(42)
42.0
>>> float("3.14159")
3.14159

float Methods

Method	Description
`.as_integer_ratio()`	Returns a pair of integers whose ratio is exactly equal to the original `float`.
`.is_integer()`	Returns `True` if the float instance is finite with an integral value, and `False` otherwise.
`.hex()`	Returns a representation of a floating-point number as a hexadecimal string.
`.fromhex(string)`	Constructs a `float` from a hexadecimal string.
`.from_number(x)`	Class method that constructs a `float` from a number `x`. It delegates to `x.__float__()` or falls back to `x.__index__()`. Added in Python 3.14.

float Common Use Cases

The most common use cases for the float data type include:

Performing arithmetic operations with decimal numbers
Representing scientific data using scientific notation
Conducting financial calculations where fractional values are needed
Handling measurements with precision

float Real-World Example

Consider a scenario where you need to calculate the area of a circle with a given radius using the formula area = π * radius^2. This involves floating-point arithmetic to manage precision:

>>> import math
>>> radius = 5.5
>>> area = math.pi * radius**2
>>> area
95.03317777109125

In this example, the float data type is crucial for handling the precision of the calculation, allowing for an accurate representation of the area.

Tutorial

How to Format Floats Within F-Strings in Python

In this tutorial, you'll learn how to use Python format specifiers within an f-string to allow you to neatly format a float to your required precision.

basics python

For additional information on related topics, take a look at the following resources:

Formatting Floats Inside Python F-Strings (Course)
Python Basics: Numbers and Math (Course)
Python Basics Exercises: Numbers and Math (Course)
Numbers in Python (Tutorial)
The Python math Module: Everything You Need to Know (Tutorial)
Python Built-in Functions: A Complete Guide (Tutorial)
Format Floats Within F-Strings (Quiz)
Exploring the Python math Module (Course)
Exploring Python's Built-in Functions (Course)
Python Built-in Functions: A Complete Guide (Quiz)

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By Leodanis Pozo Ramos • Updated Oct. 3, 2026 • Reviewed by Brenda Weleschuk and Dan Bader

Python’s Built-in Data Types Share Feedback

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