Evaluate resistor values for electronics projects using color code and circuit formulas.
Overview
Resistor calculations are essential for circuit design, current limiting, and voltage division.
This tool decodes band colors and supports equivalent resistance calculations.
Use tolerance values to account for component variation.
Steps
Select color-code decode or resistance combination mode.
Provide band colors or resistor values directly.
Determine nominal ohms and tolerance range.
Calculate series or parallel equivalent resistance.
Apply outputs to current and voltage calculations.
Math
Series: Req = Sum(R_i); Parallel: 1/Req = Sum(1/R_i)
Equivalent resistance depends on whether components are in series or parallel topology.
Worked cases
100+220+330
Req 650 ohms
1/(1/100+1/300)
Req 75 ohms
10*10^2 with 5% tolerance
1000 ohms +/-5%
Why use this
Questions