Math Calculators

Why Use a Math Calculator?

Everyday math — calculating a percentage tip, simplifying a fraction for a recipe, or working through a trigonometry problem — is faster and less error-prone with the right tool. Our math calculators are designed to show their work, not just give an answer. Each result includes the formula used, step-by-step breakdowns where relevant, and enough context to help you understand the underlying math, not just copy a number.

All tools work entirely in your browser. No account is required, no data is sent to a server, and results are instant on any device.

What Each Calculator Is For

Percentage Calculator

Handles the five most common percentage questions in one tool: What is X% of Y? X is what percent of Y? What percent change from X to Y? What is X increased/decreased by Y%? And what original value gives X after a Y% change? These cover the vast majority of real-world percentage problems — from calculating sale discounts and tax amounts to interpreting statistics and growth rates.

Scientific Calculator

A full-function scientific calculator supporting arithmetic, exponents, square roots, trigonometric functions (sin, cos, tan in degrees or radians), inverse trig, natural and base-10 logarithms, factorials, and mathematical constants (π and e). Designed for students, engineers, and anyone who needs more than a basic four-function calculator without installing dedicated software.

Fraction Calculator

Adds, subtracts, multiplies, and divides fractions with step-by-step solutions. Accepts proper fractions, improper fractions, and mixed numbers. Automatically simplifies results to lowest terms and converts between improper fractions and mixed numbers. Useful for cooking ratios, construction measurements, and any problem involving fractional quantities.

Core Math Concepts

How percentages work

A percentage is a ratio expressed as a fraction of 100. "X percent of Y" means X/100 × Y. Percentage change = (new − old) / old × 100. These two formulas underlie almost every percentage calculation you will encounter — tax rates, investment returns, discounts, grade scores, and statistical reporting all reduce to one of them. Knowing which form a question is asking is the key skill: "X is what percent of Y?" is a ratio question; "What is X% of Y?" is a multiplication question.

Fractions, decimals, and conversions

A fraction represents division: 3/4 means 3 divided by 4 = 0.75. To add fractions with different denominators, find a common denominator first: 1/3 + 1/4 = 4/12 + 3/12 = 7/12. To multiply fractions, multiply numerators and denominators separately: 2/3 × 3/5 = 6/15 = 2/5 after simplification. To divide by a fraction, multiply by its reciprocal: 2/3 ÷ 3/5 = 2/3 × 5/3 = 10/9 = 1 1/9. The fraction calculator handles all of these operations and shows each intermediate step.

Order of operations (PEMDAS/BODMAS)

Mathematical expressions must be evaluated in a specific order: Parentheses first, then Exponents, then Multiplication and Division (left to right), then Addition and Subtraction (left to right). This is called PEMDAS in North America or BODMAS in the UK. For example, 2 + 3 × 4 = 14 (not 20), because multiplication is performed before addition. The scientific calculator follows this order automatically and evaluates expressions as a full equation rather than left-to-right like a basic calculator.

Trigonometric functions and their applications

The three primary trigonometric functions — sine, cosine, and tangent — relate the angles of a right triangle to the ratios of its sides. sin(θ) = opposite/hypotenuse, cos(θ) = adjacent/hypotenuse, tan(θ) = opposite/adjacent. They are foundational in engineering, physics, navigation, and architecture. The scientific calculator evaluates these in both degrees and radians; radians are the standard unit in calculus and higher mathematics (180° = π radians), while degrees are more common in everyday geometry.

Logarithms and exponents

Exponentiation raises a base to a power: 2³ = 8. A logarithm is the inverse — it asks what power you need to raise the base to in order to get a given number: log₂(8) = 3. The natural logarithm (ln) uses base e ≈ 2.718, while log₁₀ (common log) uses base 10. Logarithms are essential in science, finance (compound interest involves exponential growth), and data analysis (log scales compress large ranges for visualization).

Frequently Asked Questions

How do I calculate a percentage of a number?

To find X% of Y, multiply Y by X/100. For example, 15% of $80 = 80 × 0.15 = $12. In the percentage calculator, enter 15 in the percentage field and 80 in the number field — the result appears instantly with the formula shown.

How do I find the percentage change between two numbers?

Percentage change = (new value − original value) / original value × 100. If a price goes from $50 to $65, the change is (65 − 50) / 50 × 100 = 30% increase. If it drops from $65 to $50, the change is (50 − 65) / 65 × 100 = −23.1% decrease. Note that a 30% increase followed by a 30% decrease does not return to the original value.

How do I add fractions with different denominators?

Find the least common denominator (LCD) of the two fractions, convert each fraction to an equivalent fraction with that denominator, then add the numerators. For example, 1/4 + 1/6: the LCD of 4 and 6 is 12. Convert: 3/12 + 2/12 = 5/12. The fraction calculator does this automatically and shows each step.

What is the difference between degrees and radians?

Degrees divide a full circle into 360 equal parts. Radians measure angles as the length of the arc on a unit circle: a full circle = 2π radians ≈ 6.283. To convert degrees to radians, multiply by π/180. To convert radians to degrees, multiply by 180/π. The scientific calculator lets you choose which unit to use for trigonometric functions.

Is this scientific calculator allowed on exams?

Our online scientific calculator is a browser-based tool intended for homework, learning, and general use. Most formal exams (SAT, ACT, standardized tests) require dedicated approved hardware calculators. Check your exam's specific calculator policy — online tools are typically not permitted during proctored tests.