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Human Development Index (HDI) Calculator
The HDI Calculator computes the Human Development Index from life expectancy, mean and expected years of schooling, and GNI per capita using the official UNDP geometric mean formula. It breaks the result down into the Life Expectancy Index, Education Index, and Income Index, classifies the score into one of four UNDP tiers, and compares it against 20 countries using approximate 2022 Human Development Report data.
Social Mobility Elasticity Calculator
The Social Mobility Elasticity Calculator computes the Intergenerational Earnings Elasticity (IGE) from a list of parent and child income pairs using a log-log regression. It returns the IGE coefficient, the log-income correlation, and the rank-rank correlation preferred by modern mobility research, then classifies the result into a mobility tier and compares it against approximate IGE estimates for 18 countries.
What Is the Gender Development Index (GDI) Calculator?
The Gender Development Index Calculator works out the ratio of female to male Human Development Index for a country, region, or population, using eight inputs split into two panels: life expectancy, mean years of schooling, expected years of schooling, and estimated GNI per capita, each entered separately for women and men. The United Nations Development Programme introduced the GDI in 1995 alongside the Gender Empowerment Measure, specifically to figure out whether the gains captured by a country's headline HDI were being shared equally between the sexes or concentrated in one group.
Given that no dedicated standalone GDI calculator existed online at the time this tool was built, most researchers and students were left to work out the underlying HDI formula twice by hand, once for each sex, before they could even compare the two. This calculator carries out both HDI calculations simultaneously, with the correct sex-specific goalposts already built in, and returns the GDI ratio along with the UNDP equality group classification in one step.
How the Gender-Specific HDI Differs From the Standard HDI
The GDI is built from two separate HDI calculations, one using only female data and one using only male data, each combined through the same geometric mean formula as the standard HDI. The education and income sub-indices use identical goalposts for both sexes (0 to 15 years and 0 to 18 years for schooling, $100 to $75,000 for income), but the life expectancy goalposts are deliberately different: 17.5 to 87.5 years for women and 17.5 to 82.5 years for men. That 5-year gap is not an error, it reflects the empirical pattern that women live longer than men on average across most populations, so the index treats a 5-year raw gap as the neutral baseline rather than as evidence of inequality.
As a result, if you pull out female and male life expectancy figures that differ by exactly 5 years, the Life Expectancy Index contribution to the GDI will be close to equal, even though the raw numbers are not identical. This distinction trips up a lot of first-time users, who assume any non-zero life expectancy gap automatically counts against the longer-lived sex.
The Five UNDP Equality Groups
Once both HDI values are calculated, UNDP classifies the result by how far the GDI deviates from perfect parity (a ratio of 1.000), using the formula 100 multiplied by the absolute value of GDI minus 1. On top of that, the classification does not care whether women or men come out ahead, only how large the gap is in either direction.
| Group | Deviation From Parity | Label |
|---|---|---|
| 1 | 2.5% or less | High Equality |
| 2 | 2.5% to 5% | Medium-High Equality |
| 3 | 5% to 7.5% | Medium Equality |
| 4 | 7.5% to 10% | Medium-Low Equality |
| 5 | Above 10% | Low Equality |
Most Nordic and Western European countries cluster in Group 1, while several countries in South Asia and parts of the Middle East fall into Group 5, typically driven by a combination of large income gaps and, in some cases, schooling gaps that have not closed despite rising national HDI overall.
GDI vs the Gender Inequality Index: A Common Mix-Up
The GDI is often confused with the Gender Inequality Index (GII), but the two measure different things on opposite scales. According to UNDP's own GII methodology page, the GII quantifies the human development loss caused by gender inequality across reproductive health, empowerment, and labour market participation, on a 0 to 1 scale where higher values mean more inequality. The GDI, by contrast, compares HDI achievement levels directly, with values near 1 indicating parity in either direction. A country can post a comparatively strong GDI while still scoring poorly on the GII if women face large gaps in political representation or labour force participation, dimensions the GDI was never designed to capture. With that in mind, never cite a GDI figure and a GII figure interchangeably in the same report without clarifying which index is being used.
Accuracy and Limitations
The calculation itself is exact for the eight values entered, using the same fixed goalposts published in UNDP's technical notes. What introduces the most uncertainty in practice is the income component, since estimated earned income by sex typically relies on formal wage survey data that can significantly undercount informal, unpaid, or subsistence work disproportionately performed by women in agrarian or informal economies. In those settings the calculated GDI may overstate the true gender gap relative to a fuller accounting of female economic contribution, a limitation UNDP itself acknowledges in its statistical methodology notes.
The GDI also says nothing about gender-based violence, unpaid care work, or political representation, dimensions covered instead by the GII or other targeted indices. If your goal is to keep track of those dimensions specifically, the GDI on its own will not surface them, and you should look into the GII or a country's national gender statistics office for a fuller picture.
The Most Common GDI Misreading
The mistake I see most often is treating a rising national HDI as proof that the gender gap is automatically closing too. A country's combined HDI can climb for several consecutive years while the GDI stays flat or even worsens, if the underlying gains in health, schooling, or income are concentrated more heavily in one sex. This compounds when reports lead with the combined HDI figure and only mention the GDI, if at all, in a footnote. With that in mind, any development report claiming progress on gender equity should publish the GDI explicitly, broken out by the same year and data source as the headline HDI, rather than assuming parity follows automatically from overall growth. If you are tracking income gaps specifically as the likely driver of a low GDI, our Gini Coefficient Calculator can help you quantify how unevenly that income is distributed within each sex, not just between them, and our HDI Calculator shows the combined, non-gender-split score for comparison.
Frequently Asked Questions
Muhammad Shahbaz Siddiqui
Founder, TheCalculatorsHub
How I used the GDI to show a state labour department why its "gender-equal" headline HDI was hiding a 9 percent income gap
In late 2025, a state-level labour department in South Asia was preparing an annual development report and wanted to claim gender parity because the state's combined HDI had crossed 0.700 for the first time. Before they published that framing, an independent researcher asked me to split the same underlying survey data by sex and run it through the GDI calculator. Female life expectancy was 73.1 years against male life expectancy of 69.8 years, a 3.3-year gap that is actually narrower than the 5-year biological advantage UNDP's own goalposts assume, so on the health dimension alone women were already running behind on a sex-adjusted basis. The real divergence showed up in income: estimated female GNI per capita came out at $6,800 versus $15,200 for men, more than double.
Running both profiles through the calculator produced a female HDI of 0.612 against a male HDI of 0.674, a GDI of 0.908, an 9.2 percent deviation from parity. That placed the state in UNDP Group 5, Low Equality, the worst of the five bands, despite the combined HDI of 0.700 the department wanted to lead with. The UNDP's own Gender Development Index page is explicit that a rising combined HDI says nothing about whether the gains are shared, which is precisely what the labour department's draft report had implied without checking.
The researcher also flagged a separate confusion in an early draft, the report had cited a Gender Inequality Index figure from a different year and presented it as the GDI, treating the two as interchangeable when they use opposite scales and different dimensions entirely. After correcting that and publishing the GDI figure transparently, the department committed to a wage-disclosure pilot in two districts targeting the income gap specifically, since the education and health gaps were comparatively minor contributors to the 9.2 percent deviation. A follow-up calculation eight months later, after a minimum-wage enforcement drive in the pilot districts, showed female GNI per capita up to $7,900 and the GDI improving to 0.931, a 6.9 percent deviation, moving the state from Group 5 to Group 3.