Square Root of 375

The square root of 375 is 5√15 in simplest radical form, or about 19.3649167310 as a decimal.

Whole numbers, decimals or fractions like 9/16. Negative numbers have no real root.
Simplest radical form
5√15
Decimal
19.364916731
Both real square roots
±19.364916731x² = 375 has two real solutions
Between
19² = 361 and 20² = 400so the root is between 19 and 20
Perfect power?
No
√37519.364916731= 5√15

Show the work

  1. Prime-factor the radicand: 375 = 3 × 53 = (52) × 3 × 5.
  2. Each pair of identical factors comes out of the radical as a single factor: √375 = 5√15.
  3. Decimal value: √375 ≈ 19.364916731.
  4. Check: 19.3649167312 ≈ 375.

√375 at a glance

Exact value
5√15
Decimal (10 places)
19.3649167310
Rounded
19.4 · 19.36 · 19.365
Perfect square?
No — between 19² and 20²
Rational?
Irrational
Both square roots
±19.364917
Prime factorization
3 × 5³
Cube root
7.211248

How to simplify √375

Look for the largest perfect square that divides 375. Here it is 25 (5²), because 375 = 25 × 15 and 15 has no square factor left:

√375 = √(25 × 15) = √25 × √15 = 5√15

The prime factorization tells the same story: 375 = 3 × 5³. Each pair of equal primes leaves the radical as one factor, so 5 comes out and 3 × 5 stays inside.

Check: (5√15)² = 5² × 15 = 25 × 15 = 375. As a decimal, 5√15 = 5 × 3.8729833462 ≈ 19.3649167310.

Where √375 sits between perfect squares

361 = 19² and 400 = 20² are the nearest perfect squares, so √375 lies between 19 and 20. 375 is 14 above 361 and 25 below 400, so the root is closer to 19.

√375 ≈ 19 + (375 − 361) ÷ (400 − 361) = 19 + 14/39 ≈ 19.3590
  • Straight line between 361 and 400: 19.3590 (0.03% low)
  • Tangent from 19, i.e. 19 + 14 ÷ 38: 19.3684 (0.02% high)
  • Tangent from 20, i.e. 20 − 25 ÷ 40: 19.3750 (0.05% high)

For √375 the tangent at 19 wins, missing by only 0.0035. Tangent estimates shine when the number sits close to a perfect square — here 375 is just 14 above 361.

1919² = 3612020² = 400√375 ≈ 19.3649
√375 on a number line, with tenths marked between 19 and 20.

Finding √375 with the Babylonian method

If a guess is too big, 375 ÷ x is too small by about the same amount, so their average lands much closer. In fact an error of e shrinks to roughly e² ÷ (2√375) in one step.

xnext = (x + 375 ÷ x) ÷ 2

Start from the nearest whole number, 19 (19² = 361):

StepGuess x375 ÷ xAverageCorrect decimals
119.000000000019.736842105319.36842105262
219.368421052619.361413043519.36491704816
319.364917048119.364916414019.3649167310all 10 shown

The count of correct decimals went 2, 6 and all 10 over 3 steps — roughly doubling each time — until the guess matched √375 = 19.3649167310 to every decimal shown.

√375 as a continued fraction

Every irrational square root has a continued fraction that repeats. For √375 the pattern is [19; 2, 1, 2, 1, 5, 1, 2, 1, 2, 38] with the block of 10 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √375 is irrational.

Cutting the continued fraction off early gives the best fractions for approximating the root — no fraction with a smaller denominator comes closer:

FractionDecimalError
19/119.00000000003.6 × 10⁻¹
39/219.50000000001.4 × 10⁻¹
58/319.33333333333.2 × 10⁻²
155/819.37500000001.0 × 10⁻²
213/1119.36363636361.3 × 10⁻³
1,220/6319.36507936511.6 × 10⁻⁴

The same fractions solve Pell’s equation, x² − 375y² = 1. Its smallest solution in positive whole numbers is x = 15,124, y = 781.

√375 in geometry and everyday measurements

  • A square patio or deck of 375 square feet is about 19.36 ft (19 ft 4 in) on each side, so edging all the way around takes 4 × √375 ≈ 77.5 ft.
  • 375 is not a sum of two whole-number squares — the prime factor 3 (one less than a multiple of 4) appears an odd number of times, which rules that out — so √375 is never the diagonal of a rectangle with whole-number sides. It is not a sum of three positive squares either, so no whole-number box has √375 as its space diagonal.
  • Since √375 = 5√15, a length of √375 is exactly 5 copies of the length √15 laid end to end.
RootSimplest formDecimalPerfect square?
√3722√9319.2873No
√373√37319.3132No
√374√37419.3391No
√3755√1519.3649No
√3762√9419.3907No
√377√37719.4165No
√3783√4219.4422No
  • The cube root of 375 is about 7.211248.
  • Squaring undoes the root: (√375)² = 375, while 375² = 140,625 — the number whose square root is 375.

Frequently asked questions

What is the square root of 375?

The square root of 375 is 5√15 in simplest radical form, which is about 19.3649167310. The negative root, −19.364917, also squares to 375.

Is the square root of 375 rational or irrational?

Irrational. 375 is not a perfect square — it falls between 361 and 400 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.

Can √375 be simplified?

Yes. The largest perfect square dividing 375 is 25, so √375 = √25 × √15 = 5√15.

What is √375 rounded to two decimal places?

√375 ≈ 19.36 to two decimal places (19.4 to one, 19.365 to three). Check: 19.36² = 374.8096, close to 375.

Need a different value? Use the Square root calculator, or browse the Square roots 1–1,000.