What utilisation is
Utilisation is the share of your working time that is billable — sold to a client at your rate. The rest is the business: finding the next client, proposals and calls that don't close, invoicing and chasing invoices, bookkeeping, the tax return, learning the tool that keeps you current, and the gaps between engagements that no calendar admits to in January.
Where 60% comes from
Agency and consultancy benchmarks have converged on the same neighbourhood for decades: individual billable roles run 65–80% utilisation inside a firm that handles their sales and admin; independents doing everything themselves reliably land lower. Sixty percent of a 46-week working year — roughly 130–140 billable days — is the honest planning figure for a solo professional. Established specialists with waiting lists run higher; anyone in their first two years runs lower.
The corollary is the arithmetic that sets rates. A $150,000 income target with $12,000 of business costs, at a 32% effective tax-and-contributions load, needs about $238,000 of gross billings; at 138 billable days, that is roughly $1,725 a day — before profit margin, buffer, or a single unpaid sick day. Divide the same target by 2,000 hours instead and you get the rate that keeps freelancers poor and busy.
Where the convention bends
Retainers raise utilisation by amortising sales effort; subcontracting through agencies raises it further and takes margin for the privilege. Project pricing converts the whole question into scoping skill. And utilisation above ~75% sustained is not success — it is deferred marketing, and it presents later as a famine quarter.
The house position
The Freelance Day Rate instrument works the full chain — target income, costs, tax, utilisation — backwards to the rate your goal actually requires, with the 60% convention printed and movable. Cross-check the result against Hourly to Salary when comparing to employment: the two pages together are the honest exchange rate between the two ways of selling a career.