Ohm's law and power
Enter any two of voltage, current and resistance to find the third, and calculate power dissipation for a circuit or component.
Free Online Electronics & Electrical Calculators
Work out the missing values in a circuit without remembering every formula. These calculators are useful for students, hobbyists and anyone prototyping electronics.
Ohm's Law Calculator
Calculate voltage, current, resistance or power from the values you already know.
NE555 Timer Calculator
Calculate resistor and capacitor values for 555 timer circuits in astable and monostable modes.
555 timer circuits
Choose astable or monostable mode, then calculate resistor and capacitor values for the frequency, period or pulse width you need.
Related toolboxes
Converting values or units? Try the math tools, or browse networking, developer and text utilities.