Square roots·80
80 =
4√5
≈ 8.944272

Square root of 80 — 8.944272 (4√5)

Irrational

The square root of 80 is about 8.944272, or exactly 4√5. It lies between 8 and 9.

As a decimal
≈ 8.944272
Simplified surd
√80 = 4√5
Between
8 < √80 < 9
Squared
80² = 6400
Cube root
∛80 ≈ 4.308869

How the surd is simplified

Pull out the largest square factor. Since 50 = 25 × 2, the root of 25 comes out as 5 and the 2 stays behind: 5√2.

80 = √(16 × 5) = 4√5

Nearby numbers

From 1 to 200

How to read this

  • The decimal is rounded; the surd form is the exact value.
  • Pulling out a square factor simplifies the surd — √50 = 5√2.
  • If the number is not a perfect square, the decimal never ends (irrational).
  • Knowing which two integers it sits between is enough to estimate in your head.

Frequently asked questions

Q. What is the square root of 80?

About 8.944272, or exactly 4√5.

Q. Can the surd be simplified?

Yes: 80 = 16 × 5, so 4 comes out and it becomes 4√5.

Q. Between which integers does it fall?

Between 8 and 9.

Q. What is the cube root of 80?

About 4.308869.