The age distribution, , in Jonschwil is; 462 children or 14.7% of the population are between 0 and 9 years old and 536 teenagers or 17.1% are between 10 and 19. Of the adult population, 369 people or 11.8% of the population are between 20 and 29 years old. 534 people or 17.0% are between 30 and 39, 499 people or 15.9% are between 40 and 49, and 385 people or 12.3% are between 50 and 59. The senior population distribution is 181 people or 5.8% of the population are between 60 and 69 years old, 94 people or 3.0% are between 70 and 79, there are 62 people or 2.0% who are between 80 and 89, and there are 12 people or 0.4% who are between 90 and 99.