The ratio of the number of marriages in a given period (usually year) to the population at mid-term, or the average number of population in this period or rate calculated in relation to the population entitled to marriages (for practical reasons, adopt the most number of people aged 15 and more which increases the possibility of comparison).

Marriage rates for different periods (month, quarter, half year, three quarters, etc.) are calculated on an annual basis, i.e. that the examined facts recorded in a given period are increased accordingly to the annual volumes, e.g. for the rate calculated for the period: month – the number of facts is multiplied by 12, quarter – by 4, half of the year – by 2, three quarters – by 4/3.