Current Transformer Ratio Calculator

Calculate CT secondary current, burden, and accuracy class requirements for metering and protection.

Expected primary current.
A
CT ratio primary value (e.g., 400 for 400:5).
:5
Total connected burden (meters + wire).
VA

Results

Secondary Current-A
% of CT Rating-%
Burden Impedance-Ω
Secondary Voltage-V
References: IEEE C57.13; IEEE C57.13.6; ANSI/IEEE C57.13