Engineering calculators

PPM / % calculator

This calculator converts from ppm ( parts per million ) to percentage, and from percentage to ppm. This is particulary useful when working out the total error contributed by a resistor.

Maximum resistor power for given heatsink

This calculator enables the user to calculate the maximum power that a resistor can dissipate with a given heatsink size and ambient temperature.

Heatsink size calculator

This calculator calculates the heatsink size for given resistor power and ambient conditions.

Inrush current limiter energy calculator

When designing a circuit that uses an inrush current limiter one of most important parameters is the energy rating of the circuit. This calculator helps determine this parameter.