Math Calculators
Percentage, algebra, geometry & arithmetic.
What Are Maths Calculators?
Maths calculators provide instant, accurate answers to arithmetic, algebraic, and geometric problems — without the risk of manual calculation errors. Whether you are a student checking your homework, a professional converting units on-site, or someone who just needs to split a bill or work out a discount in their head, these tools handle the computation so you can focus on the decision.
Percentage calculations are among the most frequently needed yet frequently miscalculated operations in everyday life. Percentages appear in discounts, tax rates, grade calculations, financial growth rates, statistics, and scientific measurements. Our percentage calculators handle all common forms: finding X% of a number, expressing one number as a percentage of another, finding the original value before a percentage change, and computing percentage increase or decrease.
Algebra and equation solving tools cover the problems that routinely appear in school curricula and professional contexts alike. Linear equation solvers find the value of an unknown variable in one step. Quadratic calculators solve second-degree equations using the standard formula and display both roots. For sequences and series, our arithmetic and geometric sequence calculators compute the nth term, sum to n terms, and common difference or ratio from any starting information.
Geometry calculators compute the properties of standard 2D and 3D shapes: area, perimeter, surface area, and volume for circles, rectangles, triangles, trapezoids, spheres, cones, cylinders, and pyramids. These tools use exact closed-form formulas and are precise regardless of the scale of the dimensions. Surveyors, architects, students, and DIY enthusiasts all benefit from having reliable geometry calculations available instantly.
Number theory tools — HCF, LCM, prime factorisation, and modular arithmetic — underpin both academic mathematics and practical applications in coding and cryptography. Combination and permutation calculators support probability work, while a scientific calculator handles trigonometric, logarithmic, and exponential expressions at any level of complexity.
All maths calculators on BrainyCalculators display the formula used alongside the result so you can verify the method independently, adapt it to a spreadsheet, or use it to understand the concept rather than just get an answer.
All Math Calculators (36)
Percentage Calculator
Calculate percentages, percentage change, and percentage of a number easily.
Fraction Calculator
Add, subtract, multiply, and divide fractions. Simplify fractions and convert to decimals.
Scientific Calculator
Full-featured scientific calculator with trigonometry, logarithms, and advanced math functions.
Algebra Calculator
Solve algebraic expressions and evaluate equations step by step.
Equation Solver
Solve linear and quadratic equations for x step by step.
Quadratic Formula Calculator
Solve quadratic equations ax² + bx + c = 0 using the quadratic formula.
Matrix Calculator
Add, subtract, multiply matrices and calculate determinant and transpose.
Exponent Calculator
Calculate exponents, powers, and scientific notation instantly.
Logarithm Calculator
Calculate log base 10, natural log (ln), log base 2, and any custom base.
Root Calculator
Calculate square root, cube root, and nth root of any number.
Polynomial Calculator
Add, subtract, and multiply polynomials. Evaluate polynomials at given values.
Trigonometry Calculator
Calculate sin, cos, tan, and their inverses in degrees or radians.
Geometry Calculator
Calculate area, perimeter, volume and other properties of geometric shapes.
Area Calculator
Calculate the area of any shape — circle, triangle, rectangle, trapezoid, and more.
Volume Calculator
Calculate the volume of 3D shapes — cube, sphere, cylinder, cone, and more.
Perimeter Calculator
Calculate the perimeter or circumference of any shape easily.
Circle Calculator
Calculate the area, circumference, diameter, and radius of any circle.
Triangle Calculator
Calculate the area, perimeter, angles, and sides of any triangle.
Pythagorean Theorem Calculator
Calculate the missing side of a right triangle using the Pythagorean theorem.
Slope Calculator
Calculate slope, y-intercept, angle, and line equation from two points.
Distance Calculator
Calculate the distance between two points using the distance formula.
Prime Number Calculator
Check if a number is prime and find prime numbers up to any limit.
Factor Calculator
Find all factors and prime factors of any positive integer.
LCM Calculator
Calculate the Least Common Multiple (LCM) of two or more numbers.
GCF Calculator
Calculate the Greatest Common Factor (GCF/GCD) of two or more numbers.
Decimal to Fraction Calculator
Convert any decimal number to a simplified fraction instantly.
Fraction to Decimal Calculator
Convert any fraction to a decimal, including repeating and terminating decimals.
Scientific Notation Calculator
Convert numbers to and from scientific notation and perform arithmetic in scientific notation.
Mean Absolute Deviation Calculator
Calculate Mean Absolute Deviation (MAD) for any data set.
Sequence Calculator
Identify and calculate terms of number sequences including arithmetic, geometric, and Fibonacci.
Arithmetic Sequence Calculator
Calculate any term, sum, or common difference of an arithmetic sequence.
Geometric Sequence Calculator
Calculate any term, sum, or common ratio of a geometric sequence.
Binomial Theorem Calculator
Expand binomial expressions using the binomial theorem with full step-by-step solution.
Derivative Calculator
Calculate derivatives of common functions using differentiation rules.
Integral Calculator
Calculate definite and indefinite integrals of common functions.
Limits Calculator
Calculate limits of functions as x approaches a value using limit rules.
Math Calculator Guides
Arithmetic & Percentages
Percentage change is calculated as ((New − Old) ÷ |Old|) × 100. To find the original value before a percentage increase: Original = Current ÷ (1 + Rate/100). Before a decrease: Original = Current ÷ (1 − Rate/100). These forms are commonly needed when working backwards from a sale price, a tax-inclusive amount, or a post-growth figure.
Fraction arithmetic — addition, subtraction, multiplication, and division — follows rules that are easy to confuse under time pressure. Our fraction calculator handles mixed numbers and improper fractions, simplifies results to lowest terms, and shows each step of the working. The ratio and proportion calculator extends this to solve for unknown quantities in direct and inverse proportional relationships.
Algebra & Equations
The quadratic formula x = [−b ± √(b² − 4ac)] ÷ 2a solves any equation of the form ax² + bx + c = 0. The discriminant (b² − 4ac) determines the nature of the roots: positive gives two real roots, zero gives one repeated root, and negative gives two complex roots. Our algebra calculators display all roots and the discriminant clearly.
For linear simultaneous equations, the substitution and elimination methods both lead to the same answer — our calculator presents the solution alongside the matrix method for users who need to verify the approach. The binomial theorem calculator expands (a + b)^n for any positive integer n, listing all terms with their coefficients.
Geometry & Measurement
Area formulas vary by shape: circle = πr², triangle = ½ × base × height, rectangle = length × width, trapezoid = ½ × (a + b) × h. For 3D volumes: sphere = (4/3)πr³, cylinder = πr²h, cone = (1/3)πr²h, rectangular prism = l × w × h. Our calculators accept any unit of measurement and convert results automatically.
The Pythagorean theorem (a² + b² = c²) underpins distance, diagonal, and hypotenuse calculations across geometry, construction, and navigation. Our right-triangle calculator solves for any missing side or angle given two known values, and displays the full working for each step.
Top Math Calculators
Percentage Calculator
Find any percentage of a number, express one value as a percentage of another, or reverse-calculate the original before a change.
Algebra Calculator
Solve linear and quadratic equations, expand expressions, and find roots — with full step-by-step working displayed.
Area Calculator
Calculate the area of circles, rectangles, triangles, trapezoids, and other standard 2D shapes instantly.
Fraction Calculator
Add, subtract, multiply, and divide fractions and mixed numbers with automatic simplification and full working shown.
Scientific Calculator
Evaluate trigonometric, logarithmic, and exponential expressions — plus combinations, permutations, and modular arithmetic.
Key Formulas & References
Percentage Change
((New − Old) ÷ |Old|) × 100
Positive = increase, negative = decrease
Quadratic Formula
x = [−b ± √(b² − 4ac)] ÷ 2a
Solves ax² + bx + c = 0 for any real coefficients
Circle Area
A = π × r²
r = radius; use π ≈ 3.14159265
Pythagorean Theorem
c² = a² + b² → c = √(a² + b²)
Finds the hypotenuse c of a right triangle with legs a and b
Frequently Asked Questions About Math Calculators
Percentage change = ((New Value − Old Value) ÷ |Old Value|) × 100. A positive result is an increase; a negative result is a decrease. For example, a price rising from 80 to 100 is a 25% increase: (100 − 80) ÷ 80 × 100 = 25%.
The quadratic formula solves ax² + bx + c = 0 for x: x = [−b ± √(b² − 4ac)] ÷ 2a. The part under the square root (b² − 4ac) is called the discriminant. If it is positive, there are two real roots; if zero, one repeated root; if negative, two complex roots.
Area of a circle = π × r², where r is the radius. If you know the diameter d, the radius is d ÷ 2. For example, a circle with radius 5 has an area of π × 25 ≈ 78.54 square units.
HCF (Highest Common Factor) is the largest number that divides both values exactly. LCM (Lowest Common Multiple) is the smallest number that both values divide into exactly. HCF × LCM = Product of the two numbers, which provides a quick cross-check.
Permutations count arrangements where order matters: P(n, r) = n! ÷ (n − r)!. Combinations count selections where order does not matter: C(n, r) = n! ÷ [r! × (n − r)!]. For example, choosing 3 items from 5 gives 60 permutations but only 10 combinations.
Enter the numerators and denominators of both fractions and select the operation (add, subtract, multiply, or divide). The calculator finds a common denominator for addition and subtraction, applies the operation, simplifies the result to its lowest terms using the HCF, and shows the complete working.
Yes. Our maths calculators are designed to show full working — formulas, intermediate steps, and final results — so students can understand the method, not just copy the answer. They are useful for checking homework, understanding where an error occurred, and building familiarity with standard formulas.
BrainyCalculators Editorial Team
Our Math calculators are researched, built, and reviewed by the BrainyCalculators editorial team using industry-standard formulas and validated against authoritative references. Results are updated whenever underlying standards, rates, or guidelines change. All calculators are free, require no account, and run entirely in your browser.