An estimated 315,000 unpaid carers aged 16 to 64 in England, predominantly women, have left full-time or part-time employment to provide care. n A key threshold at which carers in England are at risk of leaving employment occurs when care is provided for 10 or more hours a week, a lower threshold than previously thought. n The public expenditure costs of carers leaving employment are estimated at £1.3 billion a year, based on the costs of Carers Allowance and lost tax revenues on foregone incomes alone.