# Sense resistor / current shunt calculator

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Too much power dissipation? You need to use a current sense amplifier ! See our Sense resistor / current shunt + current sense amplifier calculator ! **Know the value of your sense resistor already?**Use our Sense resistor power dissipation calculator

This calculator allows you to find out which sense resistor you need to drop a specified voltage at a given current. Additionally it computes the power dissipated in the sense resistor.

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[calculator-input name=“i” label=“sense current” unit=“A”][/calculator-input] [calculator-input name=“u” label=“sense voltage” unit=“V”][/calculator-input][calculator-expression name=“r” formula=“u/i” unit=“Ω”][calculator-expression name=“p” formula=“i*i*r” unit=“W”]

[calculator-output name=“sense resistor value” unit=“Ω”] A sense resistor that drops <%= format(u, “V”) %> at <%= format(i, “A”) %> needs to have a resistance of <%= format(r, “Ω”) %> and dissipates <%= format(p, “W”) %> at maximum current. [/calculator-output]

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[latex display=“true”]R_{\text{sense}} = \frac{U_{\text{drop}}}{I_{\text{sense}}}[/latex]

[latex display=“true”]P_{\text{sense}} = I_{\text{sense}}² \cdot R_{\text{sense}}[/latex]