Calculators for engineers and makers
Electrical, materials, unit conversions and maths.
Math
- Scientific CalculatorFull scientific calculator with trig, logs, powers, memory and history.
- Cubic Equation SolverSolve ax³ + bx² + cx + d = 0 for real and complex roots, with a graph.
- Complex Number CalculatorAdd, multiply, divide and raise complex numbers to powers, with polar form.
- Linear Interpolation CalculatorFind a value between two known points by linear interpolation.
- Truth Table GeneratorGenerate a truth table for any Boolean logic expression with up to 6 variables.
- Logarithm CalculatorCompute logs in base 10, base e or any base you choose.
- Matrix CalculatorAdd, multiply, invert and find determinants of matrices.
- Differential Equation SolverFirst-order linear, separable, Bernoulli, homogeneous and exact ODEs, with an initial condition and the slope field.
- Eigenvalue and Diagonalisation CalculatorEigenvalues, eigenvectors, diagonalisation, Cayley–Hamilton and quadratic forms, with exact fractions.
- Partial Derivative CalculatorPartial derivatives up to second order, Euler's theorem for homogeneous functions, and Jacobians.
- Maxima, Minima and Lagrange MultipliersMaxima, minima and saddle points of f(x, y), and constrained extremes by Lagrange multipliers.
- Taylor Series CalculatorTaylor and Maclaurin series in one or two variables, with every derivative shown.
- Beta and Gamma Function CalculatorΓ(x) and B(m, n) exactly with √π, and the sin–cos and e^(−axⁿ) integrals they evaluate.
- Double and Triple Integral CalculatorDouble and triple integrals with variable limits, in either order or polar coordinates.
- Laplace Transform CalculatorLaplace and inverse transforms, unit step, delta and convolution, and initial value problems.
- Partial Fraction CalculatorSplit a rational function into partial fractions: repeated, quadratic and improper cases, in exact fractions.
- Second-Order Differential Equation SolverLinear ODEs of any order with constant coefficients, and Cauchy–Euler equations: CF, PI and general solution.
- Gradient, Divergence and Curl CalculatorGradient, directional derivative, divergence, curl and scalar potential of fields in x, y, z.
- Root Finding CalculatorBisection, regula falsi, Newton–Raphson, secant and fixed-point iteration with the iteration table.
- Fourier Series CalculatorFourier series of any function, piecewise too, full or half range, with coefficient formulas and a partial-sum graph.
- Linear Algebra CalculatorLinear independence, Gram–Schmidt, rank and nullity, null space and least squares, with exact fractions.
- Complex Analysis CalculatorCauchy–Riemann equations, harmonic conjugates, residues and contour integrals, and the Möbius map through three points.
- Z-Transform CalculatorZ-transforms and inverse Z-transforms by partial fractions, and difference equations with initial values.
- PDE Solver (Heat, Wave, Laplace)Solve the heat, wave and Laplace equations by separation of variables, with the Fourier coefficients and graphs.
- Mean Value Theorem CalculatorVerify Rolle's, Lagrange's or Cauchy's mean value theorem and find every c.
- Volume of Revolution CalculatorVolumes by discs, washers and shells, and surface areas of revolution, as exact multiples of π.
- Fourier Transform CalculatorFourier, sine and cosine transforms of pulses, polynomial pieces and standard functions.
- Linear Transformation CalculatorMatrix of T relative to bases, change of basis, kernel and range, subspace and span tests.
- Interpolation CalculatorNewton's forward and backward differences, Lagrange's formula and divided differences, with the difference table.
- Numerical Integration CalculatorTrapezoidal rule and Simpson's 1/3 and 3/8 rules from a function or a table, with the error shown.
- Euler and Runge–Kutta CalculatorSolve dy/dx = f(x, y) by Euler, modified Euler, Heun or Runge–Kutta, step by step.
- Gauss–Seidel, Jacobi and LU CalculatorSolve linear systems by Gauss–Seidel or Jacobi iteration, or LU decomposition (Doolittle or Crout).
- Binary CalculatorAdd, subtract, multiply and divide binary numbers and convert them to decimal.
- Bitwise CalculatorDo AND, OR, XOR, NOT and shifts, with two's complement in 8 to 64 bits.
- Big Number CalculatorDo exact arithmetic on very large integers and decimals without rounding.
- 3D Lines and Planes CalculatorLines and planes in 3D: angle and shortest distance between lines, plane through three points.
- Modulo CalculatorFind the remainder when one number is divided by another.
- Markov Chain Calculatorn-step transition probabilities and the stationary distribution of a Markov chain, exactly.
- Recurrence Relation SolverClosed forms for linear recurrences like Fibonacci, from the characteristic equation, checked against the recurrence.
- Graph Theory CalculatorDegrees, connectivity, Euler paths, bipartiteness and the number of spanning trees of a graph.
- Leibniz Integral Rule CalculatorDifferentiate under the integral sign with variable limits, checked against the slope of F(t).
- Multivariable Chain Rule CalculatorTotal derivative dz/dt, or ∂z/∂u and ∂z/∂v, for z = f(x, y), each checked.
- System of Differential Equations CalculatorSolve dx/dt = ax + by, dy/dt = cx + dy by elimination, with initial conditions.
- Linear PDE CalculatorHomogeneous linear PDEs with constant coefficients: auxiliary equation, CF and PI.
- Picard and Taylor Series Method CalculatorPicard's successive approximations and Taylor's series method for dy/dx = f(x, y).
- Lagrange Linear PDE CalculatorSolve Pp + Qq = R from dx/P = dy/Q = dz/R, with the general solution φ(u, v) = 0.
- PDE Formation CalculatorForm a PDE by eliminating arbitrary constants or arbitrary functions, checked by substitution.
- Charpit's Method CalculatorNon-linear first-order PDEs: Charpit's equations and complete integrals of the standard forms.
- Vector CalculatorAdd vectors and compute dot products, cross products and magnitudes.
- Hex CalculatorDo arithmetic on hexadecimal numbers and convert them to decimal.
Date & Time
Unit Converters
- Coordinates Converter (DMS to Decimal)Convert GPS coordinates between decimal degrees and degrees, minutes, seconds.
- PPM ConverterConvert ppm, ppb, percent and mg/L, and ppm to mg/m³ for gases.
- Number Base ConverterConvert between binary, octal, decimal and hexadecimal.
- Pressure ConverterConvert psi, bar, pascals, atmospheres and mmHg.
- Energy ConverterConvert joules, calories, kilowatt-hours and BTU.
- Power ConverterConvert watts, kilowatts, horsepower and BTU per hour.
- Force ConverterConvert newtons, pound-force and kilogram-force.
- Torque ConverterConvert newton-metres, foot-pounds and kilogram-metres.
Home & Property
- Wall Framing CalculatorCount studs, plates and extras for framing a wall.
- Heat Loss CalculatorEstimate a home's heat loss and the furnace or boiler size it needs.
- Concrete CalculatorEstimate concrete volume and bags needed for slabs, footings and columns.
- Cement, Sand & Aggregate CalculatorSplit a concrete or mortar mix into cement bags, sand and aggregate quantities.
- Brick CalculatorEstimate bricks and mortar for a wall of given size.
- Stair CalculatorWork out rise, run, stringer length and number of steps for a staircase.
- Rebar CalculatorEstimate rebar length, pieces and weight for a slab grid.
Business
Statistics & Probability
Science
- Hooke's Law CalculatorFind spring force, spring constant or extension, plus the energy stored.
- Friction & Inclined Plane CalculatorWork out friction and whether an object slides on a flat surface or a slope.
- Specific Heat CalculatorCalculate heat energy with Q = mcΔT, plus heating time for a given power.
- Sun Position CalculatorFind the Sun's elevation and azimuth for any place and time.
Engineering
- Metal Weight CalculatorFind the weight of steel, aluminium and other metal bars, plates, tubes and pipes.
- Pallet & Container Loading CalculatorWork out how many boxes fit on a pallet or in a 20 ft or 40 ft container.
- Ohm's Law CalculatorSolve for voltage, current, resistance or power from any two known values.
- Power Factor CalculatorCalculate kVA, kVAR and the capacitor needed to correct power factor.
- Watts, Volts & Amps CalculatorConvert between watts, volts and amps for DC and AC circuits.
- Voltage Drop CalculatorEstimate voltage drop along a cable run by wire size and length.
- Wire Size CalculatorChoose the right wire gauge for a load, length and allowable drop.
- Resistor Color Code CalculatorDecode 4, 5 and 6-band resistor colours into resistance and tolerance.
- Series & Parallel Resistor CalculatorFind total resistance of resistors in series or parallel.
- Voltage Divider CalculatorCalculate the output voltage of a resistor divider.
- LED Resistor CalculatorFind the current-limiting resistor value for an LED.
- Battery Life CalculatorEstimate run time from battery capacity and device current draw.
- kVA CalculatorConvert between kVA, kW and amps for single and three-phase supplies.
- Gear Ratio CalculatorFind gear ratio, output speed and torque for a gear train.
- Torque CalculatorCalculate torque from force and lever arm, or from power and RPM.
- Horsepower CalculatorCalculate horsepower from torque and RPM, or from vehicle performance.
- Beam Deflection CalculatorEstimate deflection and bending moment of simply supported and cantilever beams.
- Slope & Grade CalculatorConvert between percent grade, angle and rise over run.
- Pipe Flow Rate CalculatorEstimate flow rate and velocity through a pipe.
Tech & Computing
- Hash GeneratorGenerate SHA-256, SHA-512, SHA-1, MD5 and CRC32 hashes privately in your browser.
- Chmod CalculatorConvert Unix file permissions between octal (755) and rwx notation.
- IP Subnet CalculatorWork out network, broadcast, host range and mask for an IPv4 or IPv6 subnet.
- Aspect Ratio CalculatorResize width and height while keeping an aspect ratio such as 16:9.
- Unix Timestamp ConverterConvert Unix epoch time to readable dates and back.
- Bandwidth CalculatorEstimate bandwidth needed for users, video streams or website traffic.
- RAID CalculatorCalculate usable capacity and fault tolerance for RAID levels.
- Color ConverterConvert colours between HEX, RGB, HSL and CMYK.
- PX to REM ConverterConvert pixels to rem and em units for CSS.
- Uptime / SLA CalculatorConvert an SLA percentage into allowed downtime per day, month and year.
- PC Power Supply CalculatorEstimate the PSU wattage a PC build needs from its components.
- Base64 Encoder & DecoderEncode text to Base64 or decode Base64 back to text.
- URL Encoder & DecoderPercent-encode text for a URL or decode an encoded URL.