The age distribution, , in Walenstadt is; 579 children or 12.8% of the population are between 0 and 9 years old and 637 teenagers or 14.1% are between 10 and 19. Of the adult population, 523 people or 11.5% of the population are between 20 and 29 years old. 747 people or 16.5% are between 30 and 39, 642 people or 14.2% are between 40 and 49, and 545 people or 12.0% are between 50 and 59. The senior population distribution is 378 people or 8.3% of the population are between 60 and 69 years old, 315 people or 7.0% are between 70 and 79, there are 148 people or 3.3% who are between 80 and 89, and there are 18 people or 0.4% who are between 90 and 99.