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Population & demographics
All demographic data for Piancastagnaio: population, births, deaths, balances and historical trends.
Income & tax data
Average income, median income, income brackets and historical trends for Piancastagnaio.
Environment & air quality
Air quality (PM2.5, PM10, NO2) and land consumption data for Piancastagnaio.
Piancastagnaio is a small municipality in the province of Siena, Toscana region. With a population of 3839 inhabitants and a density of 55 per km², it covers an area of 69.3 km². The average declared income is 22.226 €.
Piancastagnaio in numbers: the analysis
Demographic projections to 2050 estimate about 2,996 inhabitants for Piancastagnaio: an expected decline of 22% from today.
The ageing index is one of the starkest signals: in Piancastagnaio there are 299 residents over 65 for every 100 under 14, well above the national average.
The census record tells a story of long decline: in 1951 Piancastagnaio had 5,324 inhabitants; today (2026) it has 3,839 — 27.9% fewer.
Among the 35 municipalities of the province of Siena, Piancastagnaio ranks 19 by population.
Compared with the provincial average of Siena (about 7,414 residents per municipality), Piancastagnaio is a markedly smaller centre.
Population Trend
| Anno | Popolazione |
|---|---|
| 2019 | 4127 |
| 2020 | 4094 |
| 2021 | 4016 |
| 2022 | 3968 |
| 2023 | 3882 |
| 2024 | 3867 |
| 2025 | 3849 |
| 2026 | 3839 |
Male/Female Ratio
| Valore | % | |
|---|---|---|
| Men | 1867 | 48.6% |
| Women | 1972 | 51.4% |
Demographic Statistics
Demographic Indices
Births (recent years)
| Valore | |
|---|---|
| 2021 | 29 |
| 2022 | 19 |
| 2023 | 20 |
| 2024 | 18 |
| 2025 | 20 |
Historical Population (1951-present)
| Anno | Population |
|---|---|
| 1951 | 5324 |
| 1961 | 5583 |
| 1971 | 4697 |
| 1981 | 4410 |
| 1991 | 4401 |
| 2001 | 4196 |
| 2011 | 4176 |
| 2019 | 4127 |
| 2020 | 4094 |
| 2021 | 4016 |
| 2022 | 3968 |
| 2023 | 3882 |
| 2024 | 3867 |
| 2025 | 3849 |
| 2026 | 3839 |
Marital Status (2025)
| Valore | % | |
|---|---|---|
| Single | 3264 | 42.4% |
| Married | 3366 | 43.7% |
| Divorced | 308 | 4.0% |
| Widowed | 760 | 9.9% |
School-Age Population (2026)
Total 0-18 years: 518
| Valore | |
|---|---|
| Nido (0-2) | 58 |
| Infanzia (3-5) | 78 |
| Primaria (6-10) | 133 |
| Medie (11-13) | 91 |
| Superiori (14-18) | 158 |
Foreign residents
Foreign presence and top citizenships
Embed this chart
Use the Piancastagnaio population pyramid on your site or article — the DatiItalia source link is already included.
<a href="https://datitalia.eu/comune/piancastagnaio-052020" title="Population pyramid of Piancastagnaio — DatiItalia"><img src="https://datitalia.eu/render/chart/piramide/piancastagnaio-052020" alt="Population pyramid of Piancastagnaio — DatiItalia" width="600" style="max-width:100%;height:auto;border:0" loading="lazy" /></a>