It’s pretty simple to work out your gambling budget. First off, you add up all your expenses (including both vital living expenses like bills, rent, groceries, childcare), the money you want to save and the money you want to spend on fun stuff. Then take that figure away from your total income.
Then you’re left with the money you could spend on gambling without it majorly affecting your life. You don’t need to have all of that as your gambling budget. Perhaps you want to up your savings a little. But this is a rough guideline as to what your budget could be.
There are online tools at various responsible gambling websites that can help you work out your gambling budget, including this one. This one even breaks down the percentage of your income you spend on each thing, including your current gambling spend.
These calculators can be handy to get a rough idea of what you should aim for, but remember to really rack your brains on how much you actually spend on all the different parts of your life.