Electronic Tools

Free online calculators for electronics and prototyping. No sign-up required.

Resistor Color Code Calculator

Select the color bands to decode the resistance value, or enter a value to find its color code. Supports 4, 5, and 6-band resistors.

Enter any two of Voltage, Current, Resistance, and Power — the other two are calculated instantly. Supports all common electronic unit prefixes.

Add up to 10 resistors and calculate the equivalent resistance for series or parallel circuits. Supports Ω, kΩ, and MΩ units.

Enter any 3 of the 4 values (Vin, R1, R2, Vout) and calculate the missing one, plus the current through the divider.

Decode 3-digit, 4-digit, and EIA-96 markings on SMD resistors. Enter a code to get the value, or a value to get all possible codes.

Calculate frequency, period, and duty cycle in astable mode, or pulse width in monostable mode. All resistance and capacitance units supported.