How to find power efficiency in DC-DC converter circuit
E_out / E_in = ... But then you fill in the input values for Eout and the output values for Ein???

Why not take it in 2 steps:

Input power= 0.5V*0.268A = 0.134W

Output power: 3.3V * 33uA = 109 uW.

Then Pout/Pin = 109uW/0.134W = 0.000813 = 0.081 %

The 1225 you get is simply 1/0.000813.

Your output power is very low which is unsurprising as your load is a 100 k resistor which means only little current can flow meaning almost no power is dissipated in the load.

It is quite pointless to calculate efficiency with such a light load! In this situation the quiescent current is determining the power consumption.