Electronics

Free electronics calculators for Ohm's law, resistors, wire gauge, batteries and signals, with the formula and the units shown at every step of the working.

7 calculators

Power & running costs

Electricity CalculatorPower, voltage, current and resistance, from any two.Electricity Cost CalculatorRunning cost of an appliance from its watts and hours.

Circuits & signals

Bandwidth CalculatorFile transfer time from a file size and a bandwidth.IP Subnet CalculatorNetwork address, broadcast and host range from a CIDR block.

Displays & projection

PPI CalculatorPixel density from screen resolution and diagonal size.Projector CalculatorThrow distance and image size for a projector setup.Screen Size CalculatorScreen dimensions and aspect ratio from a diagonal.

Other categories

Every calculator on CalcMax, grouped by what you are trying to work out.

MathPercentages, fractions, geometry, algebra and number bases.FinanceLoans, mortgages, interest, tax and investment returns.PhysicsMotion, forces, electricity, thermodynamics and optics.Health & FitnessBMI, calories, body fat, heart rate and nutrition targets.StatisticsAverages, standard deviation, probability and grade curves.Date & TimeAge, date differences, durations, time zones and conversions.ConstructionConcrete, gravel, mulch, paint, tile and square footage.BiologyGenetics, populations, microbiology and animal dosing.SportsPace, splits, running and cycling performance metrics.ChemistryMolarity, dilutions, reactions and stoichiometry.Food & CookingRecipe scaling, baking ratios, cooking conversions.AutomotiveFuel cost, gas mileage and trip planning.OtherBra sizing and random password generation.