Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Nominal resistance (Ω)

Required number input.

Tolerance (%)

Required number input.

Compute the maximum resistance as nominal ohms times (1 + tolerance percent / 100). The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Maximum resistance (Ω)

The resulting maximum resistance returned as a number.

• Resistor value, power, noise, and color-code calculations must account for tolerance, temperature coefficient, voltage coefficient, pulse rating, working voltage, package thermal resistance, ambient temperature, and mounting. Required steady-state power should include the manufacturer's derating curve.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Min Resistance

  Compute the minimum resistance as nominal ohms times (1 - tolerance percent / 100).

• I2C Pullup Max

  Compute the maximum I2C pull-up resistance from the bus rise time and total bus capacitance using Rp(max) = trise / (0.8473 x Cb).

• Max Power Load

  Find the load resistance in ohms that absorbs maximum power from a source, equal to the source resistance by the maximum power transfer theorem.