Science & Engineering

67 free online calculators — instant results, no sign-up

Ohm's Law CalculatorV=IR — solve any two of voltage, current, resistance Electric Power CalculatorP=VI, energy consumption and electricity cost Resistor Series & Parallel CalculatorEquivalent resistance comparison Renovation Cost EstimatorFull/half-package estimate by floor area Tile Quantity CalculatorPieces, boxes and total cost Wavelength CalculatorFrequency to wavelength — λ=c/f Force CalculatorF=ma — Newton's second law NEWDensity Calculatorρ=m/V — density, mass and volume Speed of Sound CalculatorSound speed from air temperature Paint CalculatorLiters and buckets from area and coats Flooring CalculatorPurchase area with waste allowance from room size Half-Life CalculatorRemaining amount or required time for radioactive decay and drug metabolism Molar Mass CalculatorMolecular weight from chemical formula with element breakdown Free Fall CalculatorHeight, time and impact velocity on Earth, Moon or Mars Ideal Gas Law CalculatorPV = nRT — solve pressure, volume, moles or temperature Dilution CalculatorC1V1 = C2V2 for stock volume, final concentration or volume Kinetic & Potential EnergyEk=½mv² and Ep=mgh with real-world equivalents Heat Capacity CalculatorQ=cmΔT heat energy and heating time estimate Lightning Distance CalculatorFlash-to-thunder seconds to distance, safety rules Acceleration CalculatorSolve a, v, u, t, s with kinematic equations Projectile Motion CalculatorRange, max height and flight time at any angle pH CalculatorpH, pOH, H+ concentration and acid dilution Velocity CalculatorSolve v, s, t — three-way with unit conversion Momentum Calculatorp=mv, impulse and impact force Potential Energy CalculatorEp=mgh with multi-planet gravity LED Resistor CalculatorNearest E24 value and power rating Voltage Divider CalculatorVout=Vin·R2/(R1+R2), forward and reverse Battery Life CalculatormAh ÷ mA with real-world derating Wind Chill & Heat Index CalculatorFeels-like temperature — Canadian & NOAA formulas Weight on Other PlanetsYour weight on 11 solar system bodies Geo Distance CalculatorHaversine great-circle distance, city presets Decibel CalculatordB to ratio, multi-source summation Pendulum Period CalculatorT=2π√(L/g), multiple planets Centripetal Force CalculatorF=mv²/r, rpm conversion, g-force Depth of Field CalculatorHyperfocal distance, full frame/APS-C presets RC Circuit CalculatorTime constant, charging curve Hooke's Law CalculatorF=kx, elastic potential energy Kepler's Third Law CalculatorT²=a³, planet table Buoyancy CalculatorArchimedes principle, float or sink Resistor Color Code4/5-band decode & encode, E24 series Exposure Calculator (EV)EV value, equivalent combos, ND stops Heat Index CalculatorNOAA feels-like temp, risk levels Dew Point CalculatorT+RH ↔ dew point, condensation check Transformer CalculatorTurns ratio, voltage & current Lens Calculator1/f=1/u+1/v, image type, magnification Pressure CalculatorP=F/S and liquid P=ρgh Lever CalculatorF1·L1=F2·L2, three lever types Pulley CalculatorForce saving, mechanical efficiency Molarity Calculatormol/L, mass fraction, ppm conversion Friction CalculatorStatic/kinetic friction + incline Torque Calculatorτ=rF·sinθ, power-speed conversion Refraction CalculatorSnell's law + critical angle Mass-Energy CalculatorE=mc² + TNT equivalent Gravitational Force CalculatorF=GmM/r² + surface gravity Three-Phase Power CalculatorP=√3UIcosφ + star/delta Gear Ratio CalculatorTeeth/speed/torque + multi-stage LC Resonance Calculatorf=1/(2π√LC) + 3-way solver Pipe Flow CalculatorQ=vA + sizing + velocity guide Time Dilation CalculatorLorentz factor + twin paradox Doppler Effect CalculatorSource/observer + frequency shift Thermal Expansion CalculatordL=a*L*dT · material alpha table Centrifuge RPM-RCF ConverterBidirectional · protocol reference Voltage Drop CalculatorSingle/three-phase · wire sizing · 5% rule Stopping Distance CalculatorReaction + braking · surface friction Chemical Equation BalancerBalance any equation · conservation check · steps Stoichiometry CalculatorAuto-balance · mass/moles/gas volume from coefficients Work & Power CalculatorW=Fs·cosθ · P=W/t · P=Fv · kWh/horsepower