Measurement tool

Shunt Resistor Calculator

Calculate the resistance and power dissipation of a DC current shunt from rated current and target millivolt drop.

Calculate Shunt Resistance

Estimate DC shunt resistance and power dissipation from full-scale current and target millivolt drop.

Calculator Inputs

Use the full-scale DC current that will flow through the shunt.

Calculation Results

Enter values above to see calculation results

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Calculation history
Result notes. Keep inputs, assumptions, and result together before using this value in project records.

Keep the entered values, assumptions, and result together when adding this calculation to job notes or submittal records. Final installation choices should align with the applicable code edition, equipment listing, manufacturer instructions, local amendments, and AHJ requirements.

Formula and field context

Calculate the resistance and power dissipation of a DC current shunt from rated current and target millivolt drop.

Formula context

Current Shunt Voltage Chart

A current shunt voltage chart is a calculator-led measurement worksheet. It connects current, shunt resistance, and millivolt output with meter range, lead layout, burden, and calibration review before using the reading.

Formula

Shunt voltage = current x shunt resistance.

Variables to keep with the result

  • Current is the measured or expected current through the shunt.
  • Shunt resistance is the calibrated resistance value of the shunt.
  • Shunt voltage is the millivolt signal measured across the sense terminals.
  • Meter and lead details affect accuracy and heating, especially at high current.

Use for meter and DC shunt planning

The calculation helps compare common 50 mV, 60 mV, 75 mV, and 100 mV shunt ratings before selecting a catalog part.

Thermal rating is essential

A shunt must be selected with adequate power rating, temperature behavior, terminals, enclosure conditions, and measurement accuracy.

Common Questions

What is a shunt resistor used for?
A shunt resistor creates a small voltage drop proportional to current so a meter or measurement input can read DC current.
Why does power dissipation matter?
The shunt converts some current into heat. The selected part must safely handle that heat in the installed environment.
Is this for AC current transformers?
No. This calculation is for DC shunt resistor sizing, not CT burden or AC current transformer selection.