R3CK0N

Square root of 61

√61 ≈ 7.8102. The square root of 61 is about 7.8102. 61 is not a perfect square, so √61 is irrational: its decimals never end or repeat.

√61 at a glance.
Value7.81024968
Rounded7.8 (1 dp) · 7.81 (2 dp) · 7.810 (3 dp)
Simplest radical form√61
Perfect square?No — between 7² = 49 and 8² = 64
61 squared3,721

Estimating √61 in your head

Start from the nearest perfect square, 8² = 64. 61 is 3 less than that. Divide the difference by twice the root, 16, and subtract it:

√61 ≈ 8 − 3 ÷ 16 ≈ 7.813

The true value is 7.8102, so the one-step estimate is off by about 0.002. The estimate always comes out slightly high, and it is closest when 61 is near a perfect square. The method is explained in estimating square roots in your head.

Can √61 be simplified?

No. 61 has no perfect-square factor besides 1, so √61 is already in simplest radical form.

Frequently asked questions

What is the square root of 61?

The square root of 61 is about 7.8102. 61 is not a perfect square, so √61 is irrational: its decimals never end or repeat.

Is 61 a perfect square?

No. It lies between 7² = 49 and 8² = 64.

What is √61 in simplest radical form?

√61 is already in simplest form: 61 has no square factor other than 1.

Practise estimating square roots

Nearby: √60 · √62 · all square roots to 150