Square Root of 400

Calculate √400 instantly — exact value, step-by-step explanation, and properties.

√400 =
20
✓ Perfect Square

How to Calculate √400

The square root of 400 is exactly 20. This is because 20 × 20 = 400. Since 400 is a perfect square, its square root is a whole number. You can verify: 20² = 20 × 20 = 400.

√400 = 20 (because 20 × 20 = 400)

Properties of √400

Perfect Square?

Yes

400 = 20², so its square root is a whole number.

Decimal Value

20

Exact integer result.

Square Root Symbol

√400

Also written as 400^(1/2) or 400^0.5 in programming.

Related Square Root Values

Reference table of square roots near 400 for quick comparison.

Number Square Root Perfect Square? Simplified
√361 19 Yes 19
√441 21 Yes 21
√324 18 Yes 18
√484 22 Yes 22
√500 22.360679 No 10√5
√289 17 Yes 17
√529 23 Yes 23
√256 16 Yes 16
√225 15 Yes 15
√576 24 Yes 24

Frequently Asked Questions

What is the square root of 400?

The square root of 400 is exactly 20. Since 400 is a perfect square, √400 = 20.

Is 400 a perfect square?

Yes, 400 is a perfect square. It equals 20², meaning 20 × 20 = 400.

How do you calculate √400 by hand?

Since 400 is a perfect square, you can find √400 by identifying which integer multiplied by itself equals 400. The answer is 20, because 20 × 20 = 400.

What is √400 in simplified radical form?

√400 = 20. Since it's a perfect square, no radical form is needed.

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