R3CK0N

Square root of 65

√65 ≈ 8.0623. The square root of 65 is about 8.0623. 65 is not a perfect square, so √65 is irrational: its decimals never end or repeat.

√65 at a glance.
Value8.06225775
Rounded8.1 (1 dp) · 8.06 (2 dp) · 8.062 (3 dp)
Simplest radical form√65
Perfect square?No — between 8² = 64 and 9² = 81
65 squared4,225

Estimating √65 in your head

Start from the nearest perfect square, 8² = 64. 65 is 1 more than that. Divide the difference by twice the root, 16, and add it:

√65 ≈ 8 + 1 ÷ 16 ≈ 8.063

The true value is 8.0623, so the one-step estimate is off by less than 0.001. The estimate always comes out slightly high, and it is closest when 65 is near a perfect square. The method is explained in estimating square roots in your head.

Can √65 be simplified?

No. 65 has no perfect-square factor besides 1, so √65 is already in simplest radical form.

Frequently asked questions

What is the square root of 65?

The square root of 65 is about 8.0623. 65 is not a perfect square, so √65 is irrational: its decimals never end or repeat.

Is 65 a perfect square?

No. It lies between 8² = 64 and 9² = 81.

What is √65 in simplest radical form?

√65 is already in simplest form: 65 has no square factor other than 1.

Practise estimating square roots

Nearby: √64 · √66 · all square roots to 150