What is the square root of 18?

Answer

4.242641

18 is not a perfect square4.242641² = 4.242641² ≈ 184.242641 × 4.242641 = ≈ 18

Need a custom calculation?

Open the full calculator with custom inputs

How We Calculated This

√n — the number which, multiplied by itself, equals n

√18 = 4.242641

Related Calculations

What is the square root of 1?1 (exact)What is the square root of 2?1.414214 What is the square root of 3?1.732051 What is the square root of 4?2 (exact)What is the square root of 5?2.236068

Calculated using verified formulas. Last updated March 2026.