Until today, the net salary calculator in Japan Life Hub showed national health insurance (国保) as one estimate for the whole country. The figure for your own city sat behind a sign-up and a subscription. It is free now, for everyone, with no account.
What you see
Under the result, choose one of 20 cities (Tokyo's 23 wards, Yokohama, Osaka, Sapporo, Fukuoka and 15 more), or "other city" for an estimate. You get the four parts of the premium: medical, elderly support, the child support part that started this fiscal year, and long-term care from age 40. Then the year, the month, and where each city's rates come from. A freelancer in Tokyo with 5,000,000 yen of revenue and 1,000,000 of expenses pays 464,765 yen a year at 45, or 38,730 a month. In Sapporo the same person pays 487,768.
The main result above still uses Tokyo's rates; this block is where the other cities are. Each city's rates are the ones it charges in fiscal 2026, and the block names the source; for Tokyo it is the Tokyo Metropolitan Government's table for the 23 wards.
The city names are in the page's language. If you are an employee, your company's health insurance (健康保険) applies instead, and the block says so; it is there for reference.
