The Index of Multiple Deprivation (IMD) is the official measure of relative deprivation used by the government in England. It ranks every small area, known as a Lower Layer Super Output Area (LSOA), from most to least deprived based on a combination of factors. These factors, or domains, include income, employment, health and disability, education skills and training, barriers to housing and services, crime, and the living environment. The IMD is widely used by researchers, policymakers and the public to understand the socio-economic conditions of different neighbourhoods.

What is the Index of Multiple Deprivation?

The IMD is produced by the Ministry of Housing, Communities and Local Government (now part of the Department for Levelling Up, Housing and Communities). It is updated roughly every four to five years, with the most recent release being the 2019 edition. Each LSOA, which typically contains around 1,500 residents or 650 households, is given a rank from 1 (most deprived) to the total number of LSOAs in England (32,844 in 2019). The rank is derived from a weighted combination of the seven domains, with income and employment each carrying a 22.5 per cent weight, health 13.5 per cent, education 13.5 per cent, barriers to housing and services 9.3 per cent, crime 9.3 per cent, and living environment 9.3 per cent. The IMD is a relative measure, meaning it compares areas against each other; it does not measure absolute poverty or affluence.

The seven domains are as follows:

How IMD relates to postcodes

Postcodes in the United Kingdom are part of the National Statistics Postcode Lookup (NSPL), which links each postcode to various geographic boundaries, including LSOAs. Because the IMD is calculated at the LSOA level, every postcode that falls within a given LSOA shares the same IMD rank and decile. This means that if you know a postcode, you can look up the IMD rank for its LSOA and get a good indication of the relative deprivation of that small neighbourhood. However, it is important to note that the IMD does not apply to individual addresses; it is a neighbourhood-level measure. Postcodes can cross LSOA boundaries in rare cases, but the NSPL assigns a single LSOA to each postcode based on the majority of addresses.

Why IMD matters for area research

For anyone researching a specific area, the IMD provides a quick and reliable snapshot of its socio-economic conditions. It is used by local authorities to allocate resources, target regeneration funding, and plan services such as health centres and job centres. Estate agents and homebuyers often consult IMD data to understand the relative affluence or deprivation of a neighbourhood, though it should be used alongside other indicators such as house prices and crime statistics. Academic researchers rely on the IMD to study patterns of inequality, health outcomes, and educational attainment. Because the IMD is updated regularly, it allows for trend analysis over time. However, users should be aware that the IMD is a relative measure: an area ranked in the most deprived 10 per cent in 2019 may not be as deprived in absolute terms as a similarly ranked area in 2015, because the overall level of deprivation in England may have changed. Despite this, the IMD remains the most comprehensive and widely accepted tool for measuring deprivation at a small area level in England.