How the calculation works
- Revenue needed = (target income + expenses + pension) × (1 + buffer).
- Working days = 260 weekdays − holiday − bank holidays − sick/training days.
- Billable days = working days × (1 − non-billable %).
- Day rate = revenue needed ÷ billable days. Hourly rate = day rate ÷ billable hours per day.
Why freelancers undercharge
Dividing a salary by 260 days assumes you bill every weekday of the year. Employees are paid for holidays, bank holidays, sick days and the time they spend in meetings. You aren't — so those costs have to be built into the rate you charge on the days you do bill.
And remember: a rate only pays if the invoice does. Late payment eats directly into your income — see what it is costing you.