√60 at a glance
- Exact value
- 2√15
- Decimal (10 places)
- 7.7459666924
- Rounded
- 7.7 · 7.75 · 7.746
- Perfect square?
- No — between 7² and 8²
- Rational?
- Irrational
- Both square roots
- ±7.745967
- Prime factorization
- 2² × 3 × 5
- Cube root
- 3.914868
How to simplify √60
Look for the largest perfect square that divides 60. Here it is 4 (2²), because 60 = 4 × 15 and 15 has no square factor left:
The prime factorization tells the same story: 60 = 2² × 3 × 5. Each pair of equal primes leaves the radical as one factor, so 2 comes out and 3 × 5 stays inside.
Check: (2√15)² = 2² × 15 = 4 × 15 = 60. As a decimal, 2√15 = 2 × 3.8729833462 ≈ 7.7459666924.
Where √60 sits between perfect squares
49 = 7² and 64 = 8² are the nearest perfect squares, so √60 lies between 7 and 8. 60 is 11 above 49 and 4 below 64, so the root is closer to 8.
- Straight line between 49 and 64: 7.7333 (0.16% low)
- Tangent from 7, i.e. 7 + 11 ÷ 14: 7.7857 (0.51% high)
- Tangent from 8, i.e. 8 − 4 ÷ 16: 7.7500 (0.05% high)
For √60 the tangent at 8 wins, missing by only 0.004. Tangent estimates shine when the number sits close to a perfect square — here 60 is just 4 below 64.
Finding √60 with the Babylonian method
Picture a rectangle with an area of 60 and one side x; the other side must be 60 ÷ x. Averaging the two sides gives a rectangle that is closer to a square, and the side of that square is exactly √60.
Start from the nearest whole number, 8 (8² = 64):
| Step | Guess x | 60 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 8.0000000000 | 7.5000000000 | 7.7500000000 | 2 |
| 2 | 7.7500000000 | 7.7419354839 | 7.7459677419 | 5 |
| 3 | 7.7459677419 | 7.7459656429 | 7.7459666924 | all 10 shown |
The count of correct decimals went 2, 5 and all 10 over 3 steps — roughly doubling each time — until the guess matched √60 = 7.7459666924 to every decimal shown.
√60 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √60 the pattern is [7; 1, 2, 1, 14] with the block of 4 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √60 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 |
|---|---|---|
| 7/1 | 7.0000000000 | 7.5 × 10⁻¹ |
| 8/1 | 8.0000000000 | 2.5 × 10⁻¹ |
| 23/3 | 7.6666666667 | 7.9 × 10⁻² |
| 31/4 | 7.7500000000 | 4.0 × 10⁻³ |
| 457/59 | 7.7457627119 | 2.0 × 10⁻⁴ |
| 488/63 | 7.7460317460 | 6.5 × 10⁻⁵ |
The same fractions solve Pell’s equation, x² − 60y² = 1. Its smallest solution in positive whole numbers is x = 31, y = 4.
√60 in geometry and everyday measurements
- A square room or garden bed covering 60 square feet measures about 7.75 ft (7 ft 9 in) along each wall.
- 60 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 √60 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 √60 as its space diagonal.
- Since √60 = 2√15, a length of √60 is exactly 2 copies of the length √15 laid end to end.
Square roots near √60 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √57 | √57 | 7.5498 | No |
| √58 | √58 | 7.6158 | No |
| √59 | √59 | 7.6811 | No |
| √60 | 2√15 | 7.7460 | No |
| √61 | √61 | 7.8102 | No |
| √62 | √62 | 7.8740 | No |
| √63 | 3√7 | 7.9373 | No |
- The cube root of 60 is about 3.914868.
- Four times the radicand doubles the root: √240 = 2 × √60 ≈ 15.491933.
Frequently asked questions
What is the square root of 60?
The square root of 60 is 2√15 in simplest radical form, which is about 7.7459666924. The negative root, −7.745967, also squares to 60.
Is the square root of 60 rational or irrational?
Irrational. 60 is not a perfect square — it falls between 49 and 64 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √60 be simplified?
Yes. The largest perfect square dividing 60 is 4, so √60 = √4 × √15 = 2√15.
What is √60 rounded to two decimal places?
√60 ≈ 7.75 to two decimal places (7.7 to one, 7.746 to three). Check: 7.75² = 60.0625, close to 60.