the amount off heat with parafin is fairly closely matched to the amount burnt ??
Not sure exact math on the heat vs. amount of paraffin burnt, but one thing clear was that my small Aladdinette II (2 inch wick) seems far more efficient and economic than the 3" wick version.
One fill of the paraffin to the top of the fuel tank in the Aladdinette II seems last for ages, and the heat output is good enough making the shed toasty warm in minutes.
It still had the old paraffin from 2 years ago half tank left in the heater on first lit, and it smelt toxic. But it still burnt ok, and the heat was great.
I got a couple of new bottles paraffin from local B&Q, and hoping them last till the end of this winter, the spring next year.