# Science & engineering calculators

> Physics, chemistry and electrical calculators: Ohm’s law, power, density, speed, force, molarity, half-life and more, in SI units.

Page: https://calculators.geekmidst.com/categories/science-engineering

- [Voltage Drop Calculator](https://calculators.geekmidst.com/calculators/voltage-drop-calculator.md): Estimate the voltage drop along a copper or aluminium cable from its size (mm² or AWG), length and current, for DC, single-phase or three-phase.
- [Horsepower Calculator](https://calculators.geekmidst.com/calculators/horsepower-calculator.md): Calculate power in horsepower, metric horsepower (PS), kilowatts and watts from torque and engine speed, or from force, distance and time.
- [Engine Horsepower Calculator](https://calculators.geekmidst.com/calculators/engine-horsepower-calculator.md): Estimate a car’s engine horsepower from its weight and quarter-mile elapsed time or trap speed, using Patrick Hale’s drag-racing formulas.
- [Resistor Calculator](https://calculators.geekmidst.com/calculators/resistor-calculator.md): Decode the colour bands on a 4-, 5- or 6-band resistor into its resistance, tolerance, minimum and maximum value and temperature coefficient.
- [Ohm’s Law Calculator](https://calculators.geekmidst.com/calculators/ohms-law-calculator.md): Enter any two of voltage, current, resistance and power to calculate the other two with Ohm’s law (V = I × R) and the power law (P = V × I).
- [Density Calculator](https://calculators.geekmidst.com/calculators/density-calculator.md): Find density from mass and volume, or the mass or volume from the other two, with results in kg/m³, g/cm³ and lb/ft³ and mixed metric and imperial units.
- [Weight Calculator](https://calculators.geekmidst.com/calculators/weight-calculator.md): Convert a mass in kg or lb into weight (the force of gravity) in newtons, kilogram-force and pound-force on Earth, the Moon and the planets.
- [Molarity Calculator](https://calculators.geekmidst.com/calculators/molarity-calculator.md): Find the grams of solute needed for a solution of given molarity and volume, or the molarity or volume from the others, in mol/L or mmol/L.
- [Molecular Weight Calculator](https://calculators.geekmidst.com/calculators/molecular-weight-calculator.md): Type a chemical formula such as C6H12O6, Ca(OH)2 or CuSO4·5H2O to get its molar mass in g/mol and the mass percentage of each element.
- [Kinetic Energy Calculator](https://calculators.geekmidst.com/calculators/kinetic-energy-calculator.md): Find kinetic energy from mass and speed, or the speed or mass behind a given energy, with J, kJ, kWh, kcal and ft·lbf and km/h, mph or m/s.
- [Potential Energy Calculator](https://calculators.geekmidst.com/calculators/potential-energy-calculator.md): Work out gravitational potential energy from mass and height, or the height or mass for a given energy, with any value of g and common units.
- [Force Calculator (F = ma)](https://calculators.geekmidst.com/calculators/force-mass-acceleration-calculator.md): Use Newton’s second law to find force from mass and acceleration, or mass or acceleration from the other two, in N, kN, lbf, kgf, m/s² or g.
- [Momentum Calculator](https://calculators.geekmidst.com/calculators/momentum-calculator.md): Calculate linear momentum from mass and velocity, or find the mass or speed for a given momentum, plus the matching kinetic energy.
- [Impulse Calculator](https://calculators.geekmidst.com/calculators/impulse-calculator.md): Find impulse from force and contact time, or from a mass’s change in velocity, and the average force during an impact or push.
- [Centripetal Force Calculator](https://calculators.geekmidst.com/calculators/centripetal-force-calculator.md): Find the centripetal force for an object moving in a circle, or the speed or radius it allows, with speed in m/s, km/h, mph, rpm or rad/s.
- [Projectile Range Calculator](https://calculators.geekmidst.com/calculators/projectile-range-calculator.md): Calculate how far a projectile travels from launch speed, angle and launch height, with flight time, peak height, impact speed and a range-by-angle table.
- [Projectile Maximum Height Calculator](https://calculators.geekmidst.com/calculators/projectile-maximum-height-calculator.md): Find the highest point of a projectile’s path from launch speed and angle, or the launch speed needed to reach a chosen peak height.
- [Simple Harmonic Motion Period Calculator](https://calculators.geekmidst.com/calculators/spring-mass-period-calculator.md): Find the period and frequency of a mass on a spring, or the mass or spring constant for a target period, with peak speed, acceleration and energy.
- [Pendulum Period Calculator](https://calculators.geekmidst.com/calculators/pendulum-period-calculator.md): Find a simple pendulum’s period from its length, or the length for a target period, using the exact large-swing correction as well as 2π√(L/g).
- [Hooke’s Law Calculator](https://calculators.geekmidst.com/calculators/hookes-law-calculator.md): Find a spring’s constant from a load and its stretch, or the force or extension from the other two, with the elastic energy stored in the spring.
- [Work Calculator](https://calculators.geekmidst.com/calculators/mechanical-work-calculator.md): Calculate the mechanical work done by a force over a distance at any angle, or the force or distance for a given amount of work, in J, kJ or ft·lbf.
- [Mechanical Power Calculator](https://calculators.geekmidst.com/calculators/mechanical-power-calculator.md): Find power from work and time or from force and speed, or the work done or time needed at a given power, in watts, kilowatts and horsepower.
- [Pressure Calculator](https://calculators.geekmidst.com/calculators/pressure-calculator.md): Calculate pressure from a force spread over an area, or the force or area for a given pressure, in Pa, kPa, MPa, bar, psi, atm or mmHg.
- [Hydrostatic Pressure Calculator](https://calculators.geekmidst.com/calculators/hydrostatic-pressure-calculator.md): Work out gauge and absolute pressure at a depth in water or any liquid, or the depth that gives a chosen pressure, from density, depth and g.
- [Buoyancy Calculator](https://calculators.geekmidst.com/calculators/buoyancy-calculator.md): Calculate the buoyant force on a submerged volume with Archimedes’ principle, and compare it with an object’s weight to see whether it floats or sinks.
- [Flow Rate Calculator](https://calculators.geekmidst.com/calculators/fluid-flow-rate-calculator.md): Find the volumetric flow rate in a round pipe from its bore and flow velocity, or the velocity or bore for a given flow, in L/s, L/min, m³/h or US gpm.
- [Reynolds Number Calculator](https://calculators.geekmidst.com/calculators/reynolds-number-calculator.md): Calculate the Reynolds number from velocity, pipe diameter and dynamic or kinematic viscosity, and see whether pipe flow is laminar, transitional or turbulent.
- [Bernoulli Equation Calculator](https://calculators.geekmidst.com/calculators/bernoulli-equation-calculator.md): Apply Bernoulli’s equation between two points in a flow to find the downstream pressure and pressure difference, or the velocity at the second point.
- [Ideal Gas Law Calculator](https://calculators.geekmidst.com/calculators/ideal-gas-law-calculator.md): Solve the ideal gas law for pressure, volume, amount of gas or temperature, with kPa, bar, atm or psi, litres or m³, and kelvin, °C or °F.
- [Gas Density Calculator](https://calculators.geekmidst.com/calculators/gas-density-calculator.md): Find the density of any gas from its pressure, temperature and molar mass using the ideal gas law, with molar volume and specific volume.
- [Heat Capacity Calculator](https://calculators.geekmidst.com/calculators/heat-capacity-calculator.md): Work out the heat needed to warm or cool a mass, or find a material’s specific heat from measured heat and temperature change, using Q = mcΔT.
- [Calorimetry Heat Transfer Calculator](https://calculators.geekmidst.com/calculators/calorimetry-heat-transfer-calculator.md): Find the equilibrium temperature when a hot object meets water or another body, and the heat exchanged, with an optional calorimeter heat capacity.
- [Thermal Expansion Calculator](https://calculators.geekmidst.com/calculators/thermal-expansion-calculator.md): Calculate how much a rod, pipe, rail or volume of liquid grows or shrinks with temperature, from its expansion coefficient and temperature change.
- [Conduction Heat Flow Calculator](https://calculators.geekmidst.com/calculators/conduction-heat-flow-calculator.md): Calculate steady heat flow through a flat layer from its thermal conductivity, area, thickness and temperatures, with heat flux, R-value and U-value.
- [Convection Heat Transfer Calculator](https://calculators.geekmidst.com/calculators/convection-heat-transfer-calculator.md): Find the convective heat flow between a surface and the surrounding air or liquid from the heat transfer coefficient, area and temperature difference.
- [Stefan–Boltzmann Radiation Calculator](https://calculators.geekmidst.com/calculators/radiation-stefan-boltzmann-calculator.md): Calculate net thermal radiation between a grey surface and large surroundings with Q = εσA(Ts⁴ − Tsur⁴), plus emitted power and radiative coefficient.
- [Mole to Mass Calculator](https://calculators.geekmidst.com/calculators/mole-to-mass-calculator.md): Convert moles to grams or grams to moles with the molar mass, and see the number of particles using the exact Avogadro constant.
- [Limiting Reagent Calculator](https://calculators.geekmidst.com/calculators/limiting-reagent-calculator.md): Find which reactant runs out first in aA + bB → cP, the theoretical yield of product in grams and how much of the excess reactant is left over.
- [Solution Dilution Calculator](https://calculators.geekmidst.com/calculators/solution-dilution-calculator.md): Work out how much stock solution to dilute, the final volume or either concentration with C₁V₁ = C₂V₂, plus the diluent to add and the dilution factor.
- [Solution pH Calculator](https://calculators.geekmidst.com/calculators/solution-ph-calculator.md): Calculate pH, pOH, [H⁺] and percent ionisation for strong or weak acids and bases from concentration and pKa or pKb, solving the full charge balance.
- [Acid–Base Titration Calculator](https://calculators.geekmidst.com/calculators/acid-base-titration-calculator.md): Find the concentration of an acid or base from a titration: titrant molarity, end-point volume, sample volume and the mole ratio in the balanced equation.
- [Nernst Equation Calculator](https://calculators.geekmidst.com/calculators/nernst-equation-calculator.md): Calculate a cell or half-cell potential from the standard potential, electrons transferred, temperature and reaction quotient with E = E° − (RT/nF) ln Q.
- [Electric Power Calculator](https://calculators.geekmidst.com/calculators/electric-power-calculator.md): Calculate real power in watts, apparent power in VA and reactive power in var from voltage, current and power factor, with daily energy in kWh.
- [Capacitor Energy Calculator](https://calculators.geekmidst.com/calculators/capacitor-energy-calculator.md): Calculate the energy stored in a capacitor and its charge from capacitance in F, mF, µF, nF or pF and the voltage across it, using E = ½CV² and Q = CV.
- [Resistors in Series and Parallel Calculator](https://calculators.geekmidst.com/calculators/resistor-series-parallel-calculator.md): Enter any list of resistor values to get the equivalent resistance in series and in parallel, using R = R₁ + R₂ + … and 1/R = 1/R₁ + 1/R₂ + ….
- [Inductive Reactance Calculator](https://calculators.geekmidst.com/calculators/inductive-reactance-calculator.md): Find the reactance of an inductor in ohms at any frequency from its inductance in H, mH or µH and the frequency in Hz, kHz or MHz, with angular frequency.
- [AC Impedance Calculator](https://calculators.geekmidst.com/calculators/ac-impedance-calculator.md): Calculate the impedance, phase angle, power factor and current of a series RLC circuit from R, L, C, frequency and voltage, with the resonant frequency.
- [RC Time Constant Calculator](https://calculators.geekmidst.com/calculators/rc-time-constant-calculator.md): Find the time constant τ = R × C of a resistor–capacitor circuit, the capacitor voltage at any time while charging or discharging, and the RC cut-off frequency.
- [RL Time Constant Calculator](https://calculators.geekmidst.com/calculators/rl-time-constant-calculator.md): Calculate the time constant τ = L ÷ R of a resistor–inductor circuit, the inductor current at any time as it rises or decays, and the RL cut-off frequency.
- [Frequency and Wavelength Calculator](https://calculators.geekmidst.com/calculators/frequency-wavelength-calculator.md): Convert between frequency and wavelength with λ = v ÷ f, using the exact speed of light in vacuum or your own wave speed, such as sound in air.
- [Thin Lens Equation Calculator](https://calculators.geekmidst.com/calculators/optical-lens-equation-calculator.md): Solve the thin lens equation 1/f = 1/do + 1/di for image distance, object distance or focal length, with magnification, image type and lens power.
- [Photon Energy Calculator](https://calculators.geekmidst.com/calculators/photon-energy-calculator.md): Find the energy of a photon from its wavelength, frequency or energy in eV with E = hf = hc/λ, using the exact SI values of h, c and the elementary charge.
- [Exponential Population Growth Calculator](https://calculators.geekmidst.com/calculators/population-growth-exponential-calculator.md): Project a population with exponential growth, continuous (N₀e^(rt)) or per-period ((1 + r)^t), with the doubling or halving time and a growth curve.
- [Logistic Growth Calculator](https://calculators.geekmidst.com/calculators/logistic-growth-calculator.md): Project an S-shaped logistic population curve from the starting size, carrying capacity and growth rate, with the time of fastest growth and a chart.
- [Signal-to-Noise Ratio Calculator](https://calculators.geekmidst.com/calculators/signal-to-noise-ratio-calculator.md): Calculate signal-to-noise ratio in decibels from signal and noise powers, RMS voltages or dBm levels, with the equivalent power and amplitude ratios.
- [Decibel to Power Ratio Converter](https://calculators.geekmidst.com/calculators/decibels-power-ratio-calculator.md): Convert two power levels into decibels, or a gain or loss in dB into power and voltage ratios, and apply it to a reference power to find the output.
- [FFT Frequency Bin Calculator](https://calculators.geekmidst.com/calculators/fourier-frequency-bin-calculator.md): Find the FFT bin spacing fs ÷ N, the Nyquist frequency, the number of bins and record length, and which bin a given frequency falls into.
- [Nyquist Rate Calculator](https://calculators.geekmidst.com/calculators/sampling-nyquist-rate-calculator.md): Find the Nyquist rate (twice the highest frequency) for a signal, check whether a sample rate is high enough, and see where an undersampled tone aliases.
- [Beam Deflection Calculator](https://calculators.geekmidst.com/calculators/beam-bending-deflection-calculator.md): Maximum deflection, bending moment and shear for a simply supported or cantilever beam under a point load or uniform load, from E, I and span.
- [Euler Buckling Load Calculator](https://calculators.geekmidst.com/calculators/euler-buckling-load-calculator.md): Find the Euler critical buckling load π²EI ÷ (KL)² of a slender column, its slenderness ratio and critical stress, and check it against yield strength.
- [Torsion Stress Calculator](https://calculators.geekmidst.com/calculators/torsion-stress-calculator.md): Calculate the maximum shear stress τ = Tr ÷ J and the angle of twist of a solid or hollow circular shaft under torque, with the polar moment J.
- [Young’s Modulus, Stress and Strain Calculator](https://calculators.geekmidst.com/calculators/young-modulus-strain-calculator.md): Calculate stress, strain and Young’s modulus from a tensile test, or predict how far a bar stretches under load from its modulus, with σ = F/A and E = σ/ε.
- [Poisson’s Ratio Calculator](https://calculators.geekmidst.com/calculators/poisson-ratio-calculator.md): Calculate Poisson’s ratio ν = −ε_lateral ÷ ε_axial from dimension changes or measured strains, plus volumetric strain and shear and bulk moduli from E.
- [Factor of Safety Calculator](https://calculators.geekmidst.com/calculators/safety-factor-calculator.md): Work out the factor of safety (strength ÷ applied stress or load), the margin of safety against a required factor, utilisation and the allowable value.
- [Bolt Torque Calculator](https://calculators.geekmidst.com/calculators/bolted-joint-torque-calculator.md): Convert between bolt tightening torque and clamp preload with T = K × F × d, and check the bolt stress as a percentage of its proof load.