Yes Coinwarz is accurate but there is another two factors that you need to consider.

First is the Bitcoin Difficulty rate which increases every two weeks and second is the price of Bitcoin.

For example I have 10th/s mining power in Hashflare which is currently giving me about 18 USD per day but recently when the BTC price hit an all time high I used to get 30 USD per day.

So I'd BTC price increases tomorrow and stays high for two weeks than you will get your ROI even early.

@wolfenlord you can contact me on Discord or steemit chat if you like my username is Arunava on both of them