Glossary

Utilisation Rate

The utilisation rate indicates what proportion of available working time is spent on billable or productive activities. It is the core KPI in project-based business.

Calculation

Utilisation Rate = Billable Hours ÷ Available Hours × 100

Available hours represent actual attendance hours after deducting statutory annual leave (minimum 5.6 weeks under the Working Time Regulations 1998), sick leave, and bank holidays — not the baseline contractual target hours. Failing to adjust the denominator will mistakenly measure statutory employee absence as lost utilisation.

Realistic Target Values

RoleTypical Target Corridor
Project team member without management responsibilities75–85%
Project Manager / Lead55–70%
Technical Lead, Sales / Business Development share40–55%
Executive Management / C-SuiteBelow 30%

Applying a flat target across all roles results in either employee burnout or a false sense of security.

Why 100 Per Cent Is the Wrong Target

Full 100% utilisation leaves no room for proposal preparation, continuing professional development (CPD) and training, internal team alignment, or buffer for project delays. Teams operating continuously above 90% risk breaching the 48-hour average weekly limit under the Working Time Regulations 1998 and lose the agility to take on urgent, short-notice client instructions — which are often the most profitable opportunities.

Common Misinterpretations

High utilisation says nothing about profitability: logging numerous hours at an unprofitable charge-out rate is worse than billing fewer hours at the right rate. For this reason, utilisation metrics must always be evaluated alongside the contribution margin per hour and recovery rates.

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