Trying to work out how much it'll cost to live alone

I'm trying to determine how much things like power, water, and internet bills would cost per month, and how much income I'd need per fortnight to cover it all. Assuming I manage to buy the apartment I'd like (big if but it also alliws me to determine how much I can afford if I rent too), the fortnightly repayments would be around $1200, groceries would be around $200 per fortnight, and rates/insurance/maintenance costs would be another $200 per fortnight. If I budget $100 per fortnight each on power, water, and phone/internet, that brings me to $1900 per fortnight. This does not include paying amounts on my credit card (which I just use for uber once per month anyway) or the money I spend on lunch/dinner during each fortnight.

Once I pay off my student loan, this will free up something like $180 per fortnight, and reducing my Kiwisaver contribution from 8% to the minimum of 3.5% will free up another $100 or so per fortnight, bringing my take-home pay per fortnight to not quite $1900. But this is what I earn now, not including the 3% pay increase I'm getting in June or the fact that that would also increase my Kiwisaver and student loan contributions with it by an amount I'm not sure on right now (and won't be able to calculate until then). There is also the $30 per fortnight I pay to my employer so I can buy discounted shares in the company, which ends in 2027 and 2028 respectively ($15 per fortnight each) which is a long-term investment and benefit once it matures and I finish paying it off.

Obviously I can't know how much things will cost in the future, or how much my pay will increase by. But if I can get a plan together now I can start to prepare and know what to aim for.