Turns out there are dozens of calculators out there that all factor in different things. Here's a few:
Anyhow - that's less important. More so, is to realise that just screwing in a couple of high efficiency light bulbs is going to make only a minor difference. Adjusting your water use will make a far bigger impact, as a staggering amount of energy is used to clean and pump the scheme water around the place, and the more water you use, the more energy will be needed to process and pump it.
Think about your air conditioning (or heating) costs. Not in dollars to you (although that will become important as prices go up on energy) but in terms of how much energy it consumes, how much carbon and pollution it will generate along with the energy. Could you insulate to make your place more efficient? There are government rebates in Australia to make the process easier on your pocket. Could you add a few square meters of roof to shade a critical area? A dark wall to soak up heat in winter?
Those sorts of changes will cost you money. Not making those sorts of changes will also cost you money - the price of energy is set to skyrocket. The difference is that making the changes will save you money in the long term and save the planet, while not making the changes will hasten global warming even more.
The point is that it has to be you that makes the changes. Become an activist, if you rent, lobby the landlord to make the changes or let you make them in return for a lease guarantee of a year or whatever. If you don't, then who will?