Science

Works out the water needed to bring a spirit down to a target ABV, including the contraction that makes ethanol and water mix to less than the sum of their volumes.

Air density from temperature, absolute pressure and humidity, treating dry air and water vapour as separate partial pressures, plus the standard atmosphere at any altitude.

Works out how much of a radioisotope is left after a given time, the activity in becquerels or curies, the half-life from two readings, and a parent-daughter chain.

Works out force five ways: Newton's second law, weight under any gravity, friction on a slope, centripetal force in a turn, and a spring under Hooke's law.

Kinematic displacement: how far an object ends up from where it started, from velocity and acceleration or from the legs of a journey, with the distance travelled beside it.

Wavelength from frequency or frequency from wavelength, for light or sound in any medium, with the period, wavenumber, photon energy and the band it falls in.

Propagates measurement uncertainty through sums, products, powers and single-variable functions, and quotes the result rounded to the uncertainty's own digit.

Picks a standard kVA rating from the connected load, single or three phase, then gives the full-load currents, the fault current and the NEC 450.3(B) protection.

Work out how far a material grows when it is heated, in length, area or volume, and the force it develops when both ends are held fast.

Solves q = m c dT for heat, mass, specific heat or temperature change, with an editable table of thirty materials, a mixing mode and the water heating curve.

Convert parts per million to ppb, ppt, percent, mg/L, g/L, mg/kg and grains per gallon, work ppm out from a mass of solute, or cross to molarity.

Estimates how fast a pool loses water by the ASHRAE form of the Carrier equation, with the water it costs, the heat it carries away and what a cover saves.

Solve PV = nRT for pressure, volume, moles or temperature in your own units, run the combined gas law between two states, and get gas density from a molar mass.

Finds the empirical formula from a percent composition or a set of masses, shows every mole step, and gives the molecular formula when you add a molar mass.

The exact parts of an E6B: the wind triangle both ways, true airspeed and density altitude from the standard atmosphere, and leg time, fuel and reserves.

Estimates corn yield in bushels per acre by the yield component method, from an ear count in a measured length of row, kernels per ear and the kernel size factor.

Works out acceleration from a change in velocity and time, from distance and time, or from net force and mass, and reports it in g as well as SI.

The vibrating string equation solved three ways: tension from pitch, pitch from tension, and both from a wire's material and diameter.

Molecular weight of a protein from its one-letter amino acid sequence, with the monoisotopic mass, molecular formula, extinction coefficient at 280 nm and theoretical pI.

Percent yield from the actual and theoretical yield, and the theoretical yield itself from the limiting reagent, its molar mass and the balanced equation.

Writes the molecular, total ionic and net ionic equation for a precipitation or neutralisation reaction, names the spectator ions and gives the solubility rule used.

Sizes a gas strut for a hinged lid or hatch from the moment balance about the hinge, giving the force per strut and the moment arm through the whole swing.

Average atomic mass from up to six isotope masses and their natural abundances, with each isotope's contribution shown and the abundances held to a total of 100 percent.

Reynolds number for a pipe, a duct, a flat plate or a body in a stream, with water and air properties from temperature and the laminar or turbulent verdict.

Head loss and pressure drop in a pipe run by Darcy-Weisbach with Colebrook, shown next to Hazen-Williams for water so the gap between the two methods is visible.

Isentropic flow relations for a perfect gas: stagnation ratios at any Mach number, choked mass flow through a nozzle, and the Mach number behind a ratio.

Solute potential from -iCRT plus pressure potential, in bars and megapascals, with the direction water moves between two solutions.

Volumetric flow rate from pipe or duct area and velocity, or from a volume and the time it took, in gpm, cfm, litres per second and cubic metres per hour at once.

Draws the Punnett square for a one-gene or two-gene cross and gives the genotype ratio, the phenotype ratio and the percentage behind every box.

Counts valence electrons, places the bonds and lone pairs, checks the octets and formal charges, and draws the structure for a single central atom.

Trace width from current and temperature rise by the IPC-2221 conductor charts, with copper weight, cross-section, resistance, voltage drop and power.

Muzzle energy in foot-pounds and joules from bullet weight in grains and velocity in feet per second, with momentum, power factor and Taylor KO.

Area moment of inertia for rectangles, tubes, pipes, I-beams and T-sections about both axes, with section modulus, radius of gyration and the parallel axis theorem.

Works out the drop from a level line over any distance, how far away your horizon is, and how much of a distant object the curve hides from view.

Converts VA to watts at a power factor and back again, with the reactive power in var, the phase angle and the current for a single or three phase supply.

Estimates how long a UPS or inverter battery bank holds a load, from the bank capacity in amp hours, the system voltage, inverter efficiency, depth of discharge and Peukert exponent.

Works out the osmolarity of a solution in mOsm/L from the molar concentration of each solute and the number of particles it dissociates into.

Turns a battery capacity in mAh and a device load in mA into a runtime, with a derating factor, and works out the life of a duty cycled device that sleeps between wakes.

Wet bulb temperature from air temperature and relative humidity using the Stull approximation, with the reverse reading for a sling psychrometer.

Works out watt hours from a power draw and a running time, from a battery's mAh or Ah rating and its voltage, or backwards into a runtime.

Turns a strong acid or base concentration into pH and pOH, works back from a measured pH, and gives the pH of a diluted solution.

Works out the molar mass of any chemical formula from a built-in periodic table, handling nested brackets, hydrates and the percentage each element contributes.

Sizes the series resistor for an LED from supply voltage, forward voltage and forward current, in E12 and E24 values, for series and parallel strings.

Adds up the five RMR89 parameter ratings and the orientation adjustment, then returns the rock mass class, stand-up time and shear strength band.

Reads 3, 4, 5 and 6 band resistor color codes into ohms with tolerance and temperature coefficient, and turns a resistance back into its bands.

Kinetic energy from mass and velocity, or the formula rearranged to recover the mass or the speed. Metric and imperial units throughout.

How hot the air actually feels once humidity is counted, from the published National Weather Service Rothfusz regression and its corrections.

Pressure altitude from field elevation and altimeter setting, then density altitude from the temperature, with ISA deviation, density ratio and an optional dew point.