√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:
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.
- 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.
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.
Start from the nearest whole number, 19 (19² = 361):
| Step | Guess x | 375 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 19.0000000000 | 19.7368421053 | 19.3684210526 | 2 |
| 2 | 19.3684210526 | 19.3614130435 | 19.3649170481 | 6 |
| 3 | 19.3649170481 | 19.3649164140 | 19.3649167310 | all 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:
| Fraction | Decimal | Error |
|---|---|---|
| 19/1 | 19.0000000000 | 3.6 × 10⁻¹ |
| 39/2 | 19.5000000000 | 1.4 × 10⁻¹ |
| 58/3 | 19.3333333333 | 3.2 × 10⁻² |
| 155/8 | 19.3750000000 | 1.0 × 10⁻² |
| 213/11 | 19.3636363636 | 1.3 × 10⁻³ |
| 1,220/63 | 19.3650793651 | 1.6 × 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.
Square roots near √375 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √372 | 2√93 | 19.2873 | No |
| √373 | √373 | 19.3132 | No |
| √374 | √374 | 19.3391 | No |
| √375 | 5√15 | 19.3649 | No |
| √376 | 2√94 | 19.3907 | No |
| √377 | √377 | 19.4165 | No |
| √378 | 3√42 | 19.4422 | No |
- 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.