Data from 2020 Population Census show an acceleration in the trend of delaying first marriages in China since 2010. The mean age at first marriage for women rose from 23.28 years in 2000 to 24.00 years in 2010 and to 27.95 years in 2020. Given that the population-weighted method is influenced by age structure, alternative methods, including rate-weighted method, the singulate mean age at marriage and net nuptiality table, are used to calculate and compare the mean age at first marriage for Chinese women. All indicators reflect the similar trend of delaying first marriage among Chinese women, with a noticeable acceleration in recent years. However, when age structure effects are removed, the increase in the mean age at first marriage for Chinese women shows a more moderate upward trend, with a delay of 2.92 to 3.78 years between 2000 and 2020, which is less than the result calculated by the population-weighted method. Across the different indicators, an initial widening and then narrowing trend in the urban-rural gap in first marriage delay is observed. After controlling for age structure, the extent of delay in first marriage is lower for all urban, town and rural women, with the difference being smaller in urban and larger in towns and rural areas.