# Wattage calculation for resistors in series

I need the formula for calculating resistor wattage when the resistors are in series. For example, say I have 3 1/4 watt 10 ohm resistors in series. What is the potential power dissipation for the entire circuit?

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Since resistors are in series, the current will be the same throughout the chain. Assuming that the voltage V across the string of resistors is constant, you can calculate the current $I={V \over R_1+R_2 +R_3+ ...}$. Power dissipated on each of the resistors: $P_i=I^2R_i$. If $P_i$ is less than the power rating of the resistor, it should dissipate the power without burning.
A string of N identical resistors in series each rated for P watts can dissipate $NP$ watts.