That's what the clients will be giving you. Out of that comes insurance and self-employment tax and additional social security (in the USA, as an example).
If you are working backwards from a fixed salary you have to also add in the dollar value of additional taxes and insurance, plus whatever other benefits you might be getting.
$120K salary at a regular job > $120K in paid invoices from clients.
If you're a consultant or contractor or whatever, even if you work 8 hours a day they are not all billable hours. There's the tedious business work to look after (record keeping, business development, etc.)
If you are working backwards from a fixed salary you have to also add in the dollar value of additional taxes and insurance, plus whatever other benefits you might be getting.
$120K salary at a regular job > $120K in paid invoices from clients.
If you're a consultant or contractor or whatever, even if you work 8 hours a day they are not all billable hours. There's the tedious business work to look after (record keeping, business development, etc.)