√ Simplest Radical Form Calculator with Steps – Free Radicals Simplifier 2026
The most comprehensive free simplest radical form calculator with step-by-step solutions. Simplify square roots (√), cube roots (∛), and nth roots. Simplify radical fractions, write expressions in radical form from rational exponents, and solve addition/subtraction of radicals — all with fully worked-out steps.
Enter any positive integer to find its simplest radical form. Choose the root index (2 for square root, 3 for cube root, or any nth root). Click an example to load it instantly.
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Simplify a radical fraction √(a/b) — including rationalizing the denominator. This simplify radical fractions calculator shows every step.
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Convert rational exponent form (like x^(m/n) or a number like 8^(2/3)) to radical form with full steps. This "write expression in radical form calculator" handles both variables and numeric values.
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Add or subtract two radical expressions. This calculator simplifies each radical first, then combines like radicals (same radicand after simplification).
📐 Step-by-Step Solution
Common square roots and cube roots in simplest radical form. Use this as a quick reference for homework, tests, and standardised exams.
Square Roots (√n) in Simplest Form
| n | Simplest Radical Form | Decimal |
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Cube Roots (∛n) in Simplest Form
| n | Simplest Radical Form | Decimal |
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Simplest Radical Form: Complete Guide with Step-by-Step Examples
A radical expression is in simplest radical form (also called simplified radical form or simplest form of a radical) when three conditions are all satisfied simultaneously. First, the radicand — the number or expression under the radical sign — has no perfect square factors (for square roots), no perfect cube factors (for cube roots), or more generally no nth power factors for the nth root. Second, there are no fractions under the radical sign. Third, there are no radical expressions in the denominator of any fraction. When all three conditions are met, the radical is fully simplified.
This free simplest radical form calculator with steps handles all cases — square roots, cube roots, fourth roots, and any nth root — and shows every step of the simplification process so you understand exactly how the answer was reached. It is the most thorough free radicals calculator available online, going well beyond simple input-output tools to give you the full mathematical working that teachers and textbooks expect.
What Is Simplest Radical Form? Definition and Rules
The term "simplest radical form" appears across pre-algebra, algebra, geometry, and precalculus courses. Understanding what makes a radical expression "simple" requires knowing the three rules:
- Rule 1 — No perfect power factors in the radicand: For a square root (√), no factor of the radicand can be a perfect square (4, 9, 16, 25, 36...). For a cube root (∛), no factor can be a perfect cube (8, 27, 64, 125...). This is the most commonly violated rule.
- Rule 2 — No fractions under the radical: √(3/5) violates this rule and must be rewritten as √15/5 by rationalizing the denominator.
- Rule 3 — No radicals in denominators: An expression like 1/√2 must be rewritten as √2/2 by multiplying top and bottom by √2. This process is called rationalizing the denominator.
Quick Test: Is a Radical in Simplest Form?
To test whether √N is in simplest form: find all the factors of N. If any factor is a perfect square (other than 1), the radical is NOT in simplest form. For example, √48 — the factors include 4 and 16, both perfect squares — so √48 is not in simplest form. The simplest form is 4√3.
How to Find Simplest Radical Form: Step-by-Step Method
There are two main methods for simplifying radicals: the prime factorization method (most reliable, works for all cases) and the perfect square factor method (faster for mentally simplifiable cases).
Method 1: Prime Factorization Method (for Square Roots)
Step 1 — Prime factorize the radicand:
180 = 2 × 90 = 2 × 2 × 45 = 2 × 2 × 9 × 5 = 2² × 3² × 5
Step 2 — Group prime factors in pairs:
180 = (2²) × (3²) × 5
Step 3 — Each pair of identical primes comes out of the radical as one copy:
√180 = √(2² × 3² × 5) = √(2²) × √(3²) × √5 = 2 × 3 × √5
Step 4 — Multiply the outside coefficients:
√180 = 6√5 ✓
Verification: 6² × 5 = 36 × 5 = 180 ✓
Method 2: Perfect Square Factor Method (Faster Mental Method)
Step 1 — Find the largest perfect square that divides 72:
Perfect squares: 4, 9, 16, 25, 36...
36 divides 72: 72 = 36 × 2
Step 2 — Apply the product rule of radicals: √(ab) = √a × √b
√72 = √(36 × 2) = √36 × √2
Step 3 — Simplify √36 = 6:
√72 = 6√2 ✓
Note: If you chose 4 instead of 36: √72 = √4 × √18 = 2√18
But √18 = √(9×2) = 3√2, so 2×3√2 = 6√2 — same answer, more steps.
How to Simplify Cube Roots to Simplest Radical Form
Simplifying cube roots (index = 3) uses the same logic, except you group prime factors in triples instead of pairs. Each complete triple of identical primes comes out of the radical as one copy.
Step 1 — Prime factorize 54:
54 = 2 × 27 = 2 × 3 × 9 = 2 × 3 × 3 × 3 = 2 × 3³
Step 2 — Group in triples for cube root:
54 = (3³) × 2
Step 3 — Each triple comes out as one copy:
∛54 = ∛(3³ × 2) = ∛(3³) × ∛2 = 3∛2
Result: ∛54 = 3∛2 ✓
Example: Simplify ∛250
250 = 2 × 125 = 2 × 5³
∛250 = ∛(5³ × 2) = 5∛2 ✓
How to Simplify Radical Fractions: Rationalizing the Denominator
Simplifying a radical fraction requires eliminating the radical from the denominator. This process is called rationalizing the denominator. There are three main scenarios:
Case 1: √(a/b) — Fraction Under the Square Root
Step 1 — Separate into two radicals: √(3/5) = √3/√5
Step 2 — Rationalize denominator (multiply by √5/√5):
√3/√5 × √5/√5 = √15/√25 = √15/5
Result: √(3/5) = √15/5 ✓
Simplify √(4/9):
√4/√9 = 2/3 (perfect squares — no radical remains!)
Case 2: Integer / √b — Rationalizing a Single Term Denominator
Step 1 — Multiply by √3/√3:
6/√3 × √3/√3 = 6√3/3 = 2√3
Result: 6/√3 = 2√3 ✓
Simplify 5/√12:
First simplify √12 = 2√3
5/(2√3) × √3/√3 = 5√3/6
Result: 5/√12 = 5√3/6 ✓
How to Write an Expression in Radical Form: Rational Exponents
The "write expression in radical form calculator" tab above converts rational (fractional) exponents to radical notation. This topic appears extensively in Algebra 2, Precalculus, and Calculus. The key rule is:
a^(m/n) = ⁿ√(aᵐ) = (ⁿ√a)ᵐ
Where: n = index of the radical (the root)
m = power of the base
Examples:
x^(1/2) = √x (square root)
x^(1/3) = ∛x (cube root)
x^(2/3) = ∛(x²) (cube root of x squared)
8^(2/3) = ∛(8²) = ∛64 = 4
16^(3/4) = ⁴√(16³) = ⁴√4096 = 8
27^(1/3) = ∛27 = 3
32^(2/5) = ⁵√(32²) = ⁵√1024 = 4
The denominator of the rational exponent always becomes the index of the radical. The numerator becomes the power of the radicand. When evaluating numeric expressions, it is usually easier to take the root first (to get a smaller number), then raise to the power.
Adding and Subtracting Radicals: Like Terms Rule
Adding and subtracting radicals follows the same principle as combining like terms in algebra: you can only combine radicals that have the same radicand and the same index (like radicals). The key insight is that two radicals which look different may become like radicals after simplification.
Step 1 — Simplify each radical separately:
√18 = √(9×2) = 3√2
√8 = √(4×2) = 2√2
Step 2 — Both are now √2 — they are like radicals!
3√2 + 2√2 = (3+2)√2 = 5√2
Result: √18 + √8 = 5√2 ✓
Example: 3√12 + 2√27
√12 = 2√3 → 3×2√3 = 6√3
√27 = 3√3 → 2×3√3 = 6√3
6√3 + 6√3 = 12√3 ✓
Example: √5 + √7
Different radicands after simplification → CANNOT combine
√5 + √7 is already in simplest form ✓
Common Mistakes When Simplifying Radicals
Students learning to simplify radicals make several recurring errors. Being aware of these mistakes dramatically reduces errors on tests and homework:
- Stopping too early: √72 = 2√18 is not fully simplified because 18 = 9×2, so 2√18 = 6√2. Always check that the radicand has no more perfect square factors.
- Incorrect product rule: √(a+b) ≠ √a + √b. The product rule only applies to multiplication: √(a×b) = √a × √b. This is one of the most common radical algebra errors.
- Incorrect squaring: (a + √b)² ≠ a² + b. The correct expansion is (a + √b)² = a² + 2a√b + b.
- Forgetting to rationalize: Leaving √2/2 as 1/√2 is not in simplest radical form — the denominator must be rationalized.
- Adding unlike radicals: √2 + √3 ≠ √5. Unlike radicals cannot be combined through addition.
- Wrong grouping for cube roots: For ∛(8x²), only 8 = 2³ comes out. The x² stays inside because you need x³ for a complete group. Result: 2∛(x²).
Simplest Radical Form on TI-84 Calculator: What You Need to Know
Many students search for "simplest radical form calculator TI 84" expecting their graphing calculator to display answers like 6√2 instead of 8.485.... Standard TI-84 calculators display decimal approximations, not exact radical forms. Here is the full picture:
- TI-84 Plus / TI-84 Plus Silver Edition: Displays decimals only. No built-in radical simplification.
- TI-84 Plus CE with Symbolic Math Guide app: The free Symbolic Math Guide (SMG) app from Texas Instruments adds some exact computation capabilities, including simplified radical display in specific contexts.
- TI-Nspire CX CAS: The CAS (Computer Algebra System) version of the TI-Nspire can display exact radical forms and simplify radicals symbolically.
- Best alternative: Use the free simplest radical form calculator with steps on this page — it shows the complete step-by-step work that no calculator (including Desmos) displays by default.
Radical Calculator vs. Desmos: Differences and Limitations
Desmos (desmos.com) is a popular graphing calculator that many students search for when looking for a "radical calculator Desmos." While Desmos is excellent for graphing radical functions, it has significant limitations for simplest radical form work:
- Desmos displays decimal approximations, not simplified radical forms
- Desmos does not show step-by-step simplification
- Desmos cannot rationalize denominators or convert between rational exponent and radical form
- Desmos does not display results like "6√2" — it shows "8.485281374..."
For simplest radical form work specifically, this dedicated simplest radical form calculator with steps provides far more educational value than Desmos, TI-84, or WolframAlpha — because it shows every step of the prime factorization, grouping, and simplification process that students need to understand for exams.
Simplest Radical Form in Geometry: Pythagorean Theorem Applications
Simplest radical form appears constantly in geometry, particularly in Pythagorean theorem applications and in the properties of 30-60-90 and 45-45-90 special right triangles.
| Triangle / Side | Expression | Simplest Radical Form | Context |
|---|---|---|---|
| Diagonal of unit square | √(1²+1²) = √2 | √2 ≈ 1.414 | 45-45-90 triangle |
| Diagonal of 2×2 square | √(4+4) = √8 | 2√2 | 45-45-90 triangle |
| Height of equilateral triangle (side 2) | √(4-1) = √3 | √3 ≈ 1.732 | 30-60-90 triangle |
| Hypotenuse, legs 3 and 4 | √(9+16) = √25 | 5 (perfect square) | 3-4-5 Pythagorean triple |
| Hypotenuse, legs 5 and 7 | √(25+49) = √74 | √74 (no simplification) | Prime radicand — done |
| Hypotenuse, legs 6 and 8 | √(36+64) = √100 | 10 | 6-8-10 = 2×(3-4-5) |
| Space diagonal of unit cube | √(1+1+1) = √3 | √3 | 3D Pythagorean theorem |
Perfect Squares and Perfect Cubes Reference: Master List
| n | n² (perfect square) | n³ (perfect cube) | n⁴ (4th power) | n⁵ (5th power) |
|---|---|---|---|---|
| 1 | 1 | 1 | 1 | 1 |
| 2 | 4 | 8 | 16 | 32 |
| 3 | 9 | 27 | 81 | 243 |
| 4 | 16 | 64 | 256 | 1024 |
| 5 | 25 | 125 | 625 | 3125 |
| 6 | 36 | 216 | 1296 | 7776 |
| 7 | 49 | 343 | 2401 | 16807 |
| 8 | 64 | 512 | 4096 | 32768 |
| 9 | 81 | 729 | 6561 | 59049 |
| 10 | 100 | 1000 | 10000 | 100000 |
| 12 | 144 | 1728 | 20736 | — |
| 15 | 225 | 3375 | — | — |
| 20 | 400 | 8000 | — | — |
Frequently Asked Questions: Simplest Radical Form
Is √2 in simplest radical form?
Yes. √2 is in simplest radical form because 2 has no perfect square factors other than 1 (2 is prime). No simplification is possible. √2 ≈ 1.41421356...
What is the simplest radical form of √50?
√50 = √(25×2) = √25 × √2 = 5√2. The simplest radical form of √50 is 5√2. Verification: (5)² × 2 = 25 × 2 = 50 ✓
Can a radical be in simplest form and still be irrational?
Yes. Most simplified radicals are irrational numbers. For example, 6√2 is in simplest radical form, but it is an irrational number (6 × 1.41421... = 8.48528...). A simplified radical equals a rational number only when the radicand is a perfect power — for example, √25 = 5 (rational) or ∛27 = 3 (rational).
What does it mean when the radicand is prime?
If the number under the radical sign is a prime number (2, 3, 5, 7, 11, 13...), the radical is already in simplest form. A prime number has no perfect square factors, so there is nothing to pull out of the radical. For example, √7, √11, and √13 are all in simplest radical form.
How do you simplify radicals with variables?
For radicals with variables, apply the same logic: group identical variable factors in pairs (for square roots). For √(x⁶), group as (x²)³ = (x²)×(x²)×(x²) — three complete pairs — so √(x⁶) = x³. For √(x⁵): group as x⁴×x, giving √(x⁵) = x²√x (four-power group gives x², one x stays inside). General rule: √(xⁿ) = x^(n/2) when n is even; = x^((n-1)/2) × √x when n is odd. The expression tab in the calculator above handles variable expressions using rational exponent notation.