All Calculators

Calculate the latent heat (Q = m·L) in joules and kilojoules absorbed or released during a phase change from the mass and specific latent heat.

Find the third side of a triangle from two sides and the included angle using the law of cosines: c = √(a² + b² − 2ab·cos(C)).

Find an unknown side of a triangle with the law of sines: enter a side, its opposite angle, and a second angle to get b = a · sin(B) / sin(A).

Add up order processing, production, and transit time to find total lead time, and compute the reorder point from daily demand and safety stock.

Calculate the series current-limiting resistor for an LED (R = (Vs − Vf) / I) in ohms and the power it must dissipate from the supply voltage, forward voltage, and current.

Convert length between metric and imperial units — millimetres, centimetres, metres, kilometres, inches, feet, yards, miles, and nautical miles.

Solve the thin-lens equation (1/f = 1/dₒ + 1/dᵢ) for the image distance and magnification from a focal length and object distance.

Apply the law of the lever to find the effort force (effort = load × loadArm ÷ effortArm) in newtons and the mechanical advantage of a lever.

Find the equation of a straight line through two points in slope-intercept form y = m·x + b — the slope and the y-intercept, computed instantly.

Estimate the value y at any point x on the straight line between two known points (x1, y1) and (x2, y2) using the linear interpolation formula.

Solve a 2×2 system of linear equations by Cramer's rule. Enter the six coefficients and get x and y instantly, with the determinant shown.

Generate a linear or IHK grade scale instantly. Distribute test points to grades 1-6 accurately, toggle half-points, and see the full grade table at a glance.

Calculate the logarithm of any number to any base with log_b(x) = ln(x) / ln(b), plus the natural logarithm ln(x).

Calculate the Lorentz factor (γ = 1 / √(1 − (v/c)²)) of special relativity from a speed, plus that speed as a percentage of the speed of light.

Calculate the Lorentz force (F = qvB) on a charge moving perpendicular to a magnetic field, in newtons, from the charge, velocity, and field strength.

Convert lumens to lux by dividing luminous flux by the area in square metres — find out how bright a room or surface will be from a given light source.

Convert lumens to watts by dividing luminous flux by efficacy (lm/W) — compare LED, CFL, halogen, and incandescent bulbs to find the right wattage for your target brightness.

Calculate the luminosity of a star (L = 4πR²σT⁴) in watts and in solar luminosities from its radius and surface temperature.

Convert lux to foot-candles instantly — enter an illuminance reading in lux (lm/m²) and get the equivalent in foot-candles (lm/ft²), the US/imperial unit used in lighting standards and photometry.

Convert illuminance in lux to total luminous flux in lumens over an area (lumens = lux × area), for sizing lights and checking lighting levels.

Calculate the Mach number (M = v / a) of an object from its speed and the local speed of sound — find out if motion is subsonic, sonic, supersonic, or hypersonic.

Calculate the magnetic flux (Φ = B × A) in webers for a magnetic field perpendicular to a flat surface, from the field strength and the area.

Calculate the magnetic force (F = BIL) in newtons on a current-carrying wire in a magnetic field from the field strength, current, and wire length.

Calculate the linear magnification (m = image height / object height) and its percentage from an image and object measured in the same unit.

Convert a battery capacity in mAh to energy in watt-hours (Wh = mAh × V / 1000) and kilowatt-hours using the pack voltage.

Calculate profit margin and markup from a cost and a selling price, with the profit per unit shown alongside.

Calculate the selling price and profit from a cost and a markup percentage, with a clear explanation of how markup differs from margin.

Calculate the rest energy of a mass with Einstein's mass-energy equivalence — energy = mass × c², where c is the speed of light.

Calculate the mass flow rate (ṁ = ρ·A·v) in kg/s and the volumetric flow rate of a fluid from its density, cross-sectional area, and velocity.

Calculate mechanical advantage from load and effort force — MA = load force ÷ effort force.

Convert milligrams to millilitres and back. Milligrams measure mass and millilitres measure volume, so you need the concentration — and this asks for it.

Find the midpoint of the line segment between two points (x1, y1) and (x2, y2) — midpoint = ((x1 + x2) / 2, (y1 + y2) / 2) — the exact centre halfway between them.

Calculate a mod n — the remainder after dividing the dividend by the divisor — plus the integer quotient, using the floored modulo definition.

Calculate molality (b = moles of solute divided by kilograms of solvent) in mol/kg from the moles of solute and the mass of the solvent.

Calculate molarity from moles and volume — molarity = moles ÷ litres of solution, in moles per litre (mol/L, also written M).

Calculate the mole fraction of each component in a two-part mixture from the amount in moles — x_A = nA / (nA + nB), with both fractions summing to 1.

Convert a mass into the amount of substance (n = m / M) in moles and the number of molecules from the mass and molar mass.

Calculate the moment of inertia (I = m·r²) of a point mass about an axis of rotation in kg·m² from its mass and its distance from the axis.

Calculate the linear momentum (p = mv) in kg·m/s and the kinetic energy of a moving object from its mass and velocity.

Calculate the output frequency, duty cycle, and high/low times of a 555 timer in astable mode from R1, R2, and the timing capacitor — f = 1.44 / ((R1 + 2·R2) × C).

Calculate the output pulse width of a 555 timer in monostable (one-shot) mode from its timing resistor and capacitor — T = 1.1 × R × C.

Calculate the net force on an object from its mass and acceleration using Newton's second law — force = mass × acceleration (F = m × a).

Calculate your weighted grade average in percent — give each grade a share, all shares should add up to 100%. Dynamically supports 2–8 grades.

Convert German upper school points to decimal grades and back.

Calculate the nth root of a number, ⁿ√x = x^(1/n), from the radicand and the degree — square roots, cube roots, and any higher root.

Calculate the area, perimeter, apothem, and circumradius of a regular octagon from its side length — area = 2(1+√2)s², perimeter = 8s, apothem = ((1+√2)/2)s, circumradius = (√(4+2√2)/2)s.

Calculate the volume, cross-section area, and surface area of a regular octagonal prism from the side length and prism length — volume = 2(1+√2)·s²·L.

The complete Ohm's law solver. Pick which two of voltage (V), current (I), resistance (R), and power (P) you know, enter them, and get the other two instantly — V = I × R, P = V × I, and every rearrangement.

Calculate the orbital period (Kepler's third law, T = 2π·√(a³/GM)) in seconds and days from the semi-major axis and the central mass.

Calculate the circular orbital velocity (v = √(GM/r)) in m/s and km/s of a body orbiting a central mass from the mass and orbital radius.