Square roots·√78
√78 =
√78
≈ 8.831761

Square root of 78 — 8.831761 (√78)

Irrational

The square root of 78 is about 8.831761, or exactly √78. It lies between 8 and 9.

As a decimal
≈ 8.831761
Simplified surd
√78 = √78
Between
8 < √78 < 9
Squared
78² = 6084
Cube root
∛78 ≈ 4.272659

Nearby numbers

√75 = 5√3√76 = 2√19√77 = √77√79 = √79√80 = 4√5√81 = 9

From 1 to 200

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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 78?

About 8.831761, or exactly √78.

Q. Can the surd be simplified?

No — there is no square factor to pull out.

Q. Between which integers does it fall?

Between 8 and 9.

Q. What is the cube root of 78?

About 4.272659.