Acceleration Calculator
Acceleration from velocity change and time, with force check.
Physics and Energy
Motion, force, energy, and circuits from first principles.
Altitude Pressure Calculator
Air pressure from elevation in both units.
Applied Pressure Calculator
Pressure from force spread over area, in psi, Pa, kPa, and atm.
Battery Life Calculator
Runtime from capacity and load, plus power bank refills.
Bernoulli Pressure Calculator
Bernoulli pressure change in Pa and psi from speed change.
Black Hole Size Calculator
Black hole event horizon radius from mass.
Boiling Point Altitude Calculator
Water boiling point from elevation.
Bolt Torque Calculator
Torque from force and wrench length, in ft-lb and N-m with exact factors.
Buoyancy Calculator
Buoyant force from displaced volume in fresh or seawater.
Capacitor Charge Calculator
Stored charge and energy of a capacitor from capacitance and voltage.
Carbon Dating Calculator
Sample age, half-lives elapsed, and range verdict from remaining carbon-14.
Carnot Efficiency Calculator
Carnot heat engine limit with fridge and heat pump COPs.
Centripetal Force Calculator
Inward force for circular motion from mass, speed, and radius.
Cloud Base Calculator
Convective cloud base from spread.
Decibel Addition Calculator
Combined noise of two or three sources in dB, with gain over loudest.
Decibel Gain Calculator
dB gain from power or voltage ratios, with multiple.
Density Altitude Calculator
Density altitude and ISA from field elevation.
Density Calculator
Density from mass and volume in metric and imperial units, with a float or sink verdict against water.
Dipole Antenna Length Calculator
Half-wave dipole feet and meters from frequency with 468 rule.
Doppler Shift Calculator
Heard pitch of a moving siren from source speed and direction.
Earthquake Energy Calculator
Released energy, TNT tons, and Hiroshima equivalents from magnitude.
Escape Velocity Calculator
Escape speed for planets and the Moon from NASA mass data.
Flywheel Energy Calculator
Stored energy, inertia, and rim speed from rotor size.
Force Calculator
Newtons, pounds force, and g force from mass times acceleration.
Free Fall Calculator
Fall time and impact speed from drop height in meters or feet.
Friction Force Calculator
Sliding friction from coefficient and normal force, with tilt angle.
Frostbite Time Calculator
Wind chill and frostbite minutes from cold and wind.
Gear Ratio Calculator
Gear ratio, output rpm, and output torque from tooth counts.
Guitar String Tension Calculator
Guitar string tension in pounds and newtons from scale, string, and tuning.
Half Life Calculator
Remaining amount after any span from starting amount and half-life.
Heating Degree Days Calculator
Heating and cooling degree days from temps.
Humidex Calculator
Canadian humidex and comfort from temps.
Hurricane Category Calculator
Saffir-Simpson category and damage from wind.
Hydroplaning Speed Calculator
Standing water lift speed from tire psi.
Inclined Plane Force Calculator
Slope push force, normal force, and grade from mass.
Kinetic Energy Calculator
Motion energy in joules and foot pounds from mass and speed.
LC Resonance Calculator
LC resonant frequency, period, and reactance.
LED Resistor Calculator
Resistor value, wattage, and actual current for any LED.
Lever Mechanical Advantage Calculator
Lever advantage, output force, and load travel from arms.
Mach Number Calculator
Mach, regime, and sound speed from airspeed.
Manning Flow Calculator
Channel velocity from Manning n, radius, slope.
Mercalli Intensity Calculator
Mercalli shaking level from magnitude.
Micro-Hydro Power Calculator
Micro-hydro kW from stream flow and head.
Moment of Inertia Calculator
Rotational inertia for six shapes, metric and imperial.
Momentum Calculator
Linear momentum from mass and velocity in SI and imperial units.
Noise Dose Calculator
NIOSH hearing dose percent from noise levels and hours.
Ohm's Law Calculator
Volts, amps, ohms, and watts from any two electrical values.
Orbital Velocity Calculator
Circular orbit speed and period from altitude for Earth, Moon, and Mars.
Parallel Resistance Calculator
Parallel equivalent for 2-4 resistors, with series sum.
Pendulum Period Calculator
Swing period, frequency, and beats per minute from length.
Photon Energy Calculator
Photon energy in eV and joules from wavelength, with frequency.
Potential Energy Calculator
Gravitational energy from mass and height, with drop speed, both systems.
Projectile Calculator
Range, peak height, and flight time from launch speed and angle.
Pulley Advantage Calculator
Lifting effort and rope pull from load weight and rope count.
Redshift Calculator
Galaxy redshift, velocity, and Hubble distance.
Resistor Color Code Calculator
Ohms, tolerance, and range from 4 band color codes.
Reynolds Number Calculator
Reynolds number, flow regime, and per length value for air and water.
Snell Law Calculator
Refraction angle from two indices, with critical angle and TIR check.
Speaker SPL Calculator
Speaker loudness at seat and watts for target SPL.
Spring Force Calculator
Spring force and stored energy from stiffness and stretch, both systems.
Spring Period Calculator
Spring oscillation period, frequency, and sag.
Terminal Velocity Calculator
Terminal fall speed from mass, area, and shape.
Thermal Expansion Calculator
Length growth from material, length, and temperature change.
Tornado EF Calculator
Enhanced Fujita rating and damage from gusts.
Transformer Calculator
Secondary volts, amps, and watts from turns ratio.
Tsunami Speed Calculator
Tsunami speed and crossing hours from depth.
Venturi Flow Calculator
Venturi throat speed and flow from diameters, pressure drop, and Cd.
Volcano VEI Calculator
Volcano VEI, plume, and size from ejecta.
Voltage Divider Calculator
Divider output volts, current, and power from Vin, R1, R2.
Voltage Drop Calculator
Volts lost, percent drop, and load volts from wire size and run.
Wavelength Calculator
Wavelength, quarter wave, and period from any frequency.
Weight on Planets Calculator
What you would weigh on every planet and the Moon.
Wien's Law Calculator
Blackbody peak nm and band from Kelvin.
Wind Power Output Calculator
Turbine power from rotor size, wind speed, air density, and Cp.
Wind Pressure Calculator
Wind psf, roof uplift, and hurricane category.
Wire Gauge Calculator (AWG to mm)
Diameter, area, and circular mils from AWG size.
Work and Power Calculator
Mechanical work in joules plus power in watts from force and time.