Order of Operations in Python

Want to understand the order of operations in Python? You write 2 * 3 - 1 and expect 5 — but only if Python evaluates multiplication before subtraction. Python does not read left to right blindly; it follows a fixed operator precedence rulebook (the same idea as PEMDAS in math).

This page maps that hierarchy: parentheses, exponentiation, multiplication/division, addition/subtraction — plus what happens when operators tie. Pair it with Operators and Operands in Python for the full operator families, and Statements vs Expressions for how expressions produce values.

What you will learn

By the end you can:

• Explain operator precedence / PEMDAS in Python
• Predict how Python evaluates mixed expressions like 2 ** 1 + 1
• Know that * and / share a level (left to right)
• Use parentheses to force intent — not just fix bugs, but aid readers
• Spot the classic degrees / 2 * pi grouping trap

We are not covering bitwise precedence, chained comparisons, or every edge case in the language reference. This page is the everyday math-expression mental model beginners need.

The rulebook Python follows

Python does not invent its own math order. It follows the same hierarchy you learned in school, often remembered as PEMDAS (Parentheses, Exponents, Multiplication/Division, Addition/Subtraction). To Python it is not a mnemonic — it is strict precedence.

When two operators share the same level, Python evaluates left to right (except **, which is right-associative — a detail you rarely need at first).

Parentheses — the highest authority

Whenever Python sees parentheses, it evaluates the inside first:

print(2 * (3 - 1))
# inside: 3 - 1 → 2
# then:    2 * 2 → 4

Another example with exponents:

print((1 + 1) ** (5 - 2))
# (1 + 1) → 2
# (5 - 2) → 3
# 2 ** 3  → 8

Parentheses do not only change results — they make intention clear. Even when not required:

(minute * 100) / 60  # same math, easier to read

Exponentiation — before multiplication

Powers happen before multiply/add:

print(2 ** 1 + 1)
# 2 ** 1 → 2
# 2 + 1  → 3   (not 2 ** 2 = 4)

If you wanted 2 ** (1 + 1), you must say so with parentheses.

Multiplication and division — equal priority

*, /, //, and % sit on the same precedence level — stronger than + and -, but not above ** or ( ).

print(2 * 3 - 1)
# 2 * 3 → 6
# 6 - 1 → 5

When priority ties — left to right

Same-level operators evaluate left to right. This matters for division and multiplication chained together:

degrees = 180
pi = 3.14159

# Python reads this as (degrees / 2) * pi
result = degrees / 2 * pi

If you meant degrees / (2 * pi), you must write the parentheses explicitly:

result = degrees / (2 * pi)

Common mistakes

• Assuming strict left-to-right for all operators
• Forgetting that / and * tie — grouping matters
• Expecting 2 ** 1 + 1 to equal 4
• Skipping parentheses when intent is unclear
• Mixing up PEMDAS with “everything left to right”

When the result surprises you

Python is not guessing or being clever — it is being consistent. If the result surprises you, it is usually precedence, not a broken interpreter. When in doubt: write what you mean. Use parentheses.