Those of you who have been exposed to electrolytic capacitors have heard of withstand voltage. The withstand voltage value of electrolytic capacitor is the operating voltage of electrolytic capacitor. For example, 6V, 16V, 25V, etc.

If the working voltage in the circuit is greater than the withstand voltage of electrolytic capacitor, the electrolytic capacitor will be easily damaged. Therefore, the capacitor withstand voltage value must be greater than the working voltage of the circuit.
The higher the value, the better. However, the larger the capacitor, the larger the size and the higher the cost. This is a waste.
If the power supply has unstable factors (such as peak voltage), it is necessary to consider the capacitor's withstand voltage value to be slightly larger, such as more than 25%.
The capacity and withstand voltage of electrolytic capacitors are marked on the capacitor's case.