Background: Postpartum haemorrhage (PPH) is the leading cause of maternal morbidity and mortality worldwide. The reported incidence of PPH varies globally, which is often due to the use of subjective visual estimation of blood loss. The aim of this study was to measure the rate of PPH and severe PPH at a UK hospital using objective measurement of blood loss. Methods: Blood loss after vaginal birth was objectively measured in 2009 women at Birmingham Women’s Hospital, UK using a blood collection drape. Results: The postpartum haemorrhage rate, defined as blood loss of 500 mL or more, was 22.2%. The severe PPH rate, defined as blood loss of 1000 mL or more, was 5.3%. Conclusions: The objective measurement of blood loss following vaginal birth is necessary for the accurate calculation of PPH rates.