Why calculate your hourly rate
Dividing your desired salary by 160 hours is the wrong math. It seems intuitive — a month has about 160 working hours — but much of your time isn't billable: prospecting, sales meetings, client management, admin and study don't go on the invoice. If you only charge for truly productive hours, the divisor is far smaller than 160, and the rate must be higher to close the month.
Net salary is not revenue. What you want to take home is only part of what you need to bill. Before it come fixed costs (software, subscriptions, study), a reserve for vacation, year-end bonus and surprises, and taxes — which fall on revenue, not on the net. That's why required revenue is higher than the salary, and tax is computed as a fraction of the total billed.
This number is a floor, not a ceiling. The minimum hourly rate is the point where you cover costs, taxes, reserve and the salary you want — working the billable hours you entered. Specific projects can (and should) charge more, depending on perceived value, urgency and complexity. Take this value to the Project pricing tool and see how it translates into a price per delivery.