How to Format Percentage in Python: Simple Guide

In Python, you can format a number as a percentage using f-strings with the :.2% format specifier or the format() method with "{:.2%}". This multiplies the number by 100 and adds a percent sign automatically.

Syntax

To format a number as a percentage in Python, use the format specifier :.2% inside an f-string or the format() method. The 2 means two decimal places. The % tells Python to multiply the number by 100 and add a percent sign.

python

value = 0.1234
formatted = f"{value:.2%}"
print(formatted)

Output

12.34%

Example

This example shows how to format a decimal number as a percentage with two decimal places using both f-string and format() method.

python

value = 0.8567

# Using f-string
percent_fstring = f"{value:.2%}"

# Using format() method
percent_format = "{:.2%}".format(value)

print(percent_fstring)
print(percent_format)

Output

85.67%
85.67%

Common Pitfalls

A common mistake is to multiply the number by 100 yourself and then format it with a percent sign, which leads to wrong results when using :.2%. Also, forgetting to use the percent sign in the format specifier will not add the % symbol.

python

# Wrong: multiplying by 100 and using :% leads to wrong output
value = 0.25
wrong = f"{value * 100:.2%}"
print(wrong)  # Output will be '2500.00%'

# Right: just use :% without multiplying
right = f"{value:.2%}"
print(right)  # Output will be '25.00%'

Output

2500.00%
25.00%

Quick Reference

Format Specifier	Description	Example Output
:.0%	No decimal places, percent sign added	12%
:.1%	One decimal place, percent sign added	12.3%
:.2%	Two decimal places, percent sign added	12.34%
:%	Default decimal places (usually 6), percent sign added	12.345679%

Key Takeaways

Use f-strings with :% to format numbers as percentages easily.

Do not multiply the number by 100 yourself when using :% format specifier.

Specify decimal places with :.2% to control precision.

The format() method also supports {:.2%} for percentage formatting.

Common mistake: multiplying by 100 and then using :% causes incorrect output.