Most of Japan's employer social insurance cost mirrors what the employee already pays: health, nursing care, and pension insurance are all straight 1:1 matches, just calculated against two DIFFERENT monthly ceilings, a higher one for health and a lower one for pension. Employment insurance is the one exception, the employer genuinely pays more than the employee, not a match.
What never shows up on an employee's payslip at all are rousai hoken and the child/childcare levy, both 100% employer-funded with zero employee contribution. Rousai hoken is priced by industry risk, an office job and a construction job carry wildly different rates. The child/childcare levy is a flat, small percentage that funds child allowance programs nationally, unrelated to whether the specific employer or employee has children.
One genuinely tricky part of Japan's 2026 landscape: a brand-new childcare support levy started collection in April 2026, layered on top of health insurance and split between employer and employee, which is a completely different program from the older child/childcare levy. This calculator includes the employer half of the new levy in the health insurance line and shows the older levy separately. The names are similar enough to cause real confusion, worth double-checking which one a specific source is actually describing.