Assuming : fast radio bursts ( FRBs ) are produced by neutron stars at cosmological distances ; FRB rate tracks the core-collapse supernova rate ; and all FRBs repeat with a universal energy distribution function ( EDF ) \mathrm { d } \dot { N } / \mathrm { d } E \propto E ^ { - \beta } with a cutoff at burst energy E _ { max } . We find that observations so far are consistent with a universal EDF with 1.5 \lesssim \beta \lesssim 2.2 , high-end cutoff E _ { max } / E _ { 0 } \gtrsim 30 and normalization \dot { N } _ { 0 } \lesssim 2 d ^ { -1 } ; where \dot { N } _ { 0 } is the integrated rate above the reference energy E _ { 0 } \simeq 1.2 \times 10 ^ { 39 } f _ { r } ^ { -1 } erg ( f _ { r } is the radio emission efficiency ) . Implications of such an EDF are discussed .