Resistor Calculator
About This Tool
Often when developing embedded electronics there are reasons you need to incorporate specific resistor ratios or voltage ratios. Common uses include feedback networks for regulators, op-amp feedback, and bias networks. Because resistors are only available in specific values, it’s not always straightforward to identify the appropriate resistors to achieve a specific ratio. This tool allows you to specify a resistor ratio in the range 0 < x ≤ 100,000 or voltage ratio in the range 0 < x < 1 and receive a list of potential options with their listed error to your target.
For all results, you may multiply or divide the results by factors of 10 if the results are not in the decade you’d like. The ‘Desired Total Resistance’ field allows you to specify a preferred sum resistance of R1 and R2 for applications where you need to limit the draw on the source.
The calculator intentionally de-prioritizes results which are separated by decades only (e.g. 2.7k/22 vs 270/2.2).
Although we’ve made our best effort to comprehensively test this tool, no guarantees as to its function are made or implied.