359 free online calculators

Keypad calculator with trig in degrees, radians or gradians, logs, powers, factorials, memory and a history tape — exact fractions where possible.

Plot several functions, polar curves and parametric curves; pan and zoom; find roots, intersections, turning points and areas.

Convert between 160 currencies at the latest daily reference rates, with the rate date and a 90-day history chart.

Find X% of Y, what percent one number is of another, percentage increase or decrease, percent difference, and the original before a percentage was added.

Add, subtract, multiply and divide fractions and mixed numbers exactly, simplify to lowest terms, and convert decimals (including repeating) to fractions.

Solve ax² + bx + c = 0 with the quadratic formula: exact roots as surds or complex numbers, the discriminant, vertex and axis of symmetry, and a graph.

Determinant, inverse, rank and RREF of a matrix up to 6 × 6 with every row operation shown, plus transpose, product and sum, in exact fractions.

Area and perimeter of 15 plane shapes, from rectangles, triangles and trapezoids to circles, ellipses, regular polygons and rings, drawn to scale.

Volume, surface area, slant height and capacity in litres for 14 solids, including cylinders, cones, spheres, pyramids, prisms, tori and ellipsoids.

Missing sides, angles, area, perimeter, heights, inradius and circumradius of any triangle from three measurements, with both SSA answers.

Hypotenuse, missing leg, both acute angles, area and perimeter of a right triangle from any two values, using Pythagoras' theorem and SOHCAHTOA.

Area, circumference, radius and diameter of a circle from any one of them, plus arc length, chord, sector and segment area for a central angle.