If you set out to live on your own, it is important that you generate enough income and that you do not live above your budget. Rule of thumb: you can spend approximately one third of your income on rent. So, with an income of €900,- do not exceed a rent of €300,-. From the remaining €600,- you will have to pay everything else. Food, clothes and your social life, but also insurances, taxes and the gas, water and electricity bills.
Use the www.jongeren.vestia.nl or JIP Rotterdam websites to make a cost calculation.