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Square root of 87

√87 ≈ 9.3274. The square root of 87 is about 9.3274. 87 is not a perfect square, so √87 is irrational: its decimals never end or repeat.

√87 at a glance.
Value9.32737905
Rounded9.3 (1 dp) · 9.33 (2 dp) · 9.327 (3 dp)
Simplest radical form√87
Perfect square?No — between 9² = 81 and 10² = 100
87 squared7,569

Estimating √87 in your head

Start from the nearest perfect square, 9² = 81. 87 is 6 more than that. Divide the difference by twice the root, 18, and add it:

√87 ≈ 9 + 6 ÷ 18 ≈ 9.333

The true value is 9.3274, so the one-step estimate is off by about 0.006. The estimate always comes out slightly high, and it is closest when 87 is near a perfect square. The method is explained in estimating square roots in your head.

Can √87 be simplified?

No. 87 has no perfect-square factor besides 1, so √87 is already in simplest radical form.

Frequently asked questions

What is the square root of 87?

The square root of 87 is about 9.3274. 87 is not a perfect square, so √87 is irrational: its decimals never end or repeat.

Is 87 a perfect square?

No. It lies between 9² = 81 and 10² = 100.

What is √87 in simplest radical form?

√87 is already in simplest form: 87 has no square factor other than 1.

Practise estimating square roots

Nearby: √86 · √88 · all square roots to 150