Calculators
Percentage, discount, GST, VAT, EMI, BMI, age, area, binary and scientific calculators plus a universal unit converter — instant and accurate.
52 free tools
Percentage Calculator
Calculate what X% of a number is, what percent one number is of another, and percentage increase or decrease between two values — instantly and free.
Discount Calculator
Work out the final sale price and money saved from any discount percentage, including stacked double discounts like an extra 10% off an already reduced price.
GST Calculator
Add GST to a net amount or extract GST from an inclusive price. Preset 5%, 12%, 18% and 28% slabs plus custom rates, with net, tax and gross shown instantly.
VAT Calculator
Add VAT to a net price or extract VAT from a gross amount. Preset 5%, 10%, 20% and 23% rates plus custom, showing net, VAT and gross values instantly.
EMI Calculator
Calculate your monthly EMI for home, car or personal loans from loan amount, interest rate and tenure — with total interest and a full amortization schedule.
BMI Calculator
Calculate your Body Mass Index from height and weight in metric (cm/kg) or imperial (ft-in/lbs) units and see your WHO category with a color-coded badge.
Age Calculator
Find your exact age in years, months and days from your date of birth, plus totals in weeks, days and hours and a countdown to your next birthday.
Binary Calculator
Do arithmetic and bitwise math on binary, decimal, hex and octal numbers — add, subtract, multiply, divide, AND, OR, XOR and shifts, with results in all bases.
Scientific Calculator
Free online scientific calculator with sin, cos, tan in degrees or radians, log, ln, powers, roots, π, e, parentheses, memory keys and keyboard support.
Unit Converter
Convert between units of length, weight, temperature, area, volume, speed, time and data storage instantly, with a swap button and common conversion tables.
Area Calculator
Calculate the area of a rectangle, triangle, circle, trapezoid or ellipse from simple measurements, with the formula shown and results in m², ft² and more.
Volume Calculator
Calculate the volume of a cube, box, sphere, cylinder, cone, pyramid, capsule or prism, with instant conversion to litres, gallons, cubic feet and yards.
Surface Area Calculator
Find total and lateral surface area for cubes, boxes, spheres, cylinders, cones, pyramids, capsules and prisms, with the exact formula shown for every shape.
Perimeter Calculator
Work out the perimeter of a rectangle, square, triangle, trapezoid, parallelogram, regular polygon, circle or ellipse in metric or imperial units.
Roof Pitch Calculator
Convert roof pitch between rise/run ratio, degrees and slope percent, and get the rafter length from the Pythagorean theorem in feet or metres.
Cubic Yard Calculator
Convert length, width and depth in feet, inches, yards, metres or centimetres into cubic yards, cubic feet and cubic metres for landscaping material orders.
Equation of a Circle Calculator
Convert a circle between general form and standard form, or build its equation from a center and radius, a point on the circle, or any three points.
Ellipse Calculator
Solve an ellipse from its semi-axes or its general equation: area, Ramanujan perimeter, eccentricity, foci, vertices, latus rectum and directrices.
Hyperbola Calculator
Find the center, vertices, foci, eccentricity, asymptote equations and latus rectum of a hyperbola from standard form or a general second-degree equation.
Triangle Centers Calculator
Enter three vertex coordinates to locate the centroid, circumcenter, incenter and orthocenter of a triangle, with the circumradius, inradius and Euler line.
Polygon Area Calculator
Paste a list of vertex coordinates to get the area of any simple polygon by the shoelace formula, plus perimeter, centroid, winding order and a convexity check.
Circle Sector and Segment Calculator
Solve a circular sector or segment from any two known values: arc length, chord, sector area, segment area, segment height and the major sector are all returned.
Hexagon Calculator
Solve a regular hexagon from any single measurement — side, area, perimeter, apothem, circumradius or either diagonal — and see how many tile a given area.
Rhombus Calculator
Solve a rhombus from two diagonals, a side and an angle, a side and its height, or a side and one diagonal, with the formula behind every number shown.
Trapezoid Calculator
Solve a trapezoid from its parallel sides plus a height, both legs or both base angles: area, median, legs, all four angles, diagonals and a scale drawing.
Golden Ratio Calculator
Split any length into golden sections with phi = 1.6180339887, build a golden rectangle and spiral, and generate a golden typographic scale for design work.
Tank Volume Calculator
Work out total capacity and the volume at any liquid depth for vertical, horizontal, rectangular, oval and capsule tanks, in litres, gallons, cubic metres and feet.
Cone Frustum Calculator
Calculate the volume, slant height and surface area of a truncated cone, and get the flat pattern radii and included angle for sheet metal or papercraft.
Derivative Calculator
Differentiate any function of x symbolically. Get f′(x) and f″(x) in simplified form, their value at a point, and a numerical check of the result.
Definite Integral Calculator
Evaluate a definite integral numerically with adaptive Simpson's rule. See the value, the error estimate and a shaded plot of the area under the curve.
Limit Calculator
Estimate the limit of a function as x approaches a value or infinity. See the full two-sided approach table and whether the limit exists at all.
Riemann Sum Calculator
Compute left, right, midpoint and trapezoidal Riemann sums with a full per-rectangle table and a drawing of the rectangles under your curve.
Tangent Line Calculator
Find the tangent and normal line to a curve at any point. Get the slope, the equation in y = mx + c form and a graph of all three together.
Newton's Method Calculator
Find a root of any function by Newton-Raphson iteration. See every step in a table with xₙ, f(xₙ), f′(xₙ) and the shrinking step size.
Euler's Method Calculator
Solve an initial value problem dy/dx = f(x, y) step by step, with an improved Euler comparison column, a full table and a plotted solution curve.
Taylor Series Calculator
Expand a function as a Taylor or Maclaurin series about any centre. Get the polynomial, the coefficients, the truncation error and the radius of convergence.
Summation Calculator
Evaluate a sigma-notation sum term by term with exact integer arithmetic, and see the standard closed-form identity beside the numeric answer.
Nth Term Calculator
Paste a sequence and find the rule behind it. Detects arithmetic, quadratic, cubic and geometric patterns and predicts any term you ask for.
Pascal's Triangle Generator
Generate Pascal's triangle to any number of rows with exact big integers, look up any C(n, k), and highlight the Sierpiński and diagonal patterns.
Binomial Expansion Calculator
Expand (ax + b)ⁿ term by term with exact coefficients, find the coefficient of any power of x, and handle fractional or negative exponents as a series.
Cone Calculator
Solve a right circular cone from any two of radius, height and slant height, with volume, lateral and total surface area, apex angle and a cutting template.
Pyramid Calculator
Solve square, rectangular and regular n-sided pyramids: volume, base area, slant height, lateral edge and surface area, or work backwards from a target volume.
Parallelogram Calculator
Find the area, perimeter, both heights, both diagonals and the angle between them from two sides and an angle, a base and height, or a side and a diagonal.
Annulus Calculator
Work out the area of a ring from its two radii, or solve for a missing radius from a target area, with sector area, arc lengths and the sector centroid.
Scale Conversion Calculator
Convert between real-world and model dimensions at any scale ratio, translate architectural scales, and apply the n² and n³ factors to area, volume and weight.
Paper Size Converter
Look up any ISO A, B, C, JIS B, ANSI or photo paper size in mm, cm, inches, points and pixels, and get the exact print scale between any two sizes.
Shoe Size Converter
Convert between UK, US men's, US women's, EU and Japanese shoe sizes using the barleycorn and Paris-point relationships, with the foot length each size fits.
Tire Size Calculator
Decode any metric or flotation tyre size into sidewall height, overall diameter and revolutions per mile, and compare two sizes for speedometer error.
Gear Ratio Calculator
Get final drive from ring and pinion teeth, then overall ratios, speed at redline in every gear, cruising RPM, crawl ratio and the axle ratio for a tyre change.
Fuel Economy Converter
Convert MPG US, MPG imperial, L/100 km, km/L and miles per litre in any direction, then cost a journey and see the real saving between two figures.
Heat Index Calculator
Work out how hot it really feels from temperature and humidity using the NWS Rothfusz regression, with the official warning band and the dew point.
Wind Chill Calculator
Apply the 2001 North American wind chill formula in Fahrenheit or Celsius, with validity limits flagged and the frostbite exposure time for the result.