Science and Engineering
Electrical, chemistry and physics calculators for students and engineers.
Voltage Drop Calculator
Calculate voltage drop across a cable run from length, current and conductor size.
Resistor Color Code Calculator
Decode a 4-band or 5-band resistor color code into its resistance value and tolerance.
Ohm's Law Calculator
Solve for voltage, current or resistance using Ohm's Law.
Electricity Cost Calculator
Estimate the monthly running cost of an appliance from its wattage and usage.
Density Calculator
Solve for density, mass or volume when you know the other two.
Mass to Weight Calculator
Convert mass to weight (force) on Earth or other planets.
Molarity Calculator
Solve for molarity, mass or volume of a solution.
Molecular Weight Calculator
Calculate the molecular weight of a chemical compound from its formula.
Half-Life Calculator
Calculate the remaining amount of a substance or the elapsed time using radioactive decay.