The acquisition of rights by workers in private pension plans underpins retirement behaviour, recruitment policy and wage structure, but there is controversy as to how these individual pension rights should be valued. The paper combines four data-sets to calculate pension entitlements for a sample of 3000 British workers in 1987. Expected scheme tenure is a key variable in valuation; younger workers and women face greater initial uncertainty as to their pension outcomes, which is resolved as job tenure lengthens. Given the distribution of tenure durations, many employees would obtain higher returns in defined contribution schemes than in a typical final-salary-defined benefit plan.