Japan Overtime Pay Calculator
Compute statutory premium pay (割増賃金) under Article 37 of the Labor Standards Act: standard overtime, monthly over-60h overtime, late-night work, holiday work, and the stacked rates that apply when they overlap.
Overtime pay calculator
How it works
How Japanese statutory overtime pay actually works
Japanese statutory overtime pay is governed by Article 37 of the Labor Standards Act (労働基準法第37条). The article sets four distinct premium rates that apply on top of the regular hourly wage, and three of them can stack with each other, producing seven effective rates depending on the kind of hour worked.
1. The four base premiums
- 1.25× for statutory overtime (法定時間外労働): hours beyond the statutory 8 per day or 40 per week.
- 1.50× for monthly overtime exceeding 60 hours: introduced for large employers in 2010, extended to all employers (including SMBs) in April 2023.
- 1.25× for late-night work (深夜労働): hours worked between 22:00 and 05:00, regardless of whether they are also overtime.
- 1.35× for holiday work (法定休日労働): hours worked on the legally guaranteed weekly rest day under Article 35 (typically Sunday).
2. The seven effective rates after stacking
Late-night, overtime, and holiday-work premiums combine. The rules are: late-night always adds 0.25 to whichever base rate applies, but holiday-work and statutory-overtime premiums do not stack with each other (a statutory holiday is not "overtime" for the purpose of the 1.25 base; it is its own category at 1.35).
- Late-night within scheduled hours: 1.25×
- Overtime ≤ 60h / month: 1.25×
- Overtime ≤ 60h / month, late-night: 1.50× (1.25 + 0.25)
- Overtime > 60h / month: 1.50×
- Overtime > 60h / month, late-night: 1.75× (1.50 + 0.25)
- Holiday work: 1.35×
- Holiday work, late-night: 1.60× (1.35 + 0.25)
3. The hourly base wage formula
The hourly rate to which all premiums are applied is computed as:
hourly = monthly base wage ÷ monthly average scheduled hours
monthly average scheduled hours = (365 − annual days off) ÷ 12 × hours per day
Example: a 300,000 yen monthly base wage with 120 days off and 8 hours per day gives
a denominator of (365 − 120) ÷ 12 × 8 = 163.33h, and an hourly rate of
300,000 ÷ 163.33 = 1,837 yen.
4. Allowances that must be excluded from the base wage
Article 21 of the enforcement regulations (労基法施行規則 第21条) lists seven categories that must be excluded when computing the overtime base, because they relate to personal circumstances rather than the work itself:
- Family allowance (家族手当)
- Commuting allowance (通勤手当)
- Separated-family allowance (別居手当)
- Children's education allowance (子女教育手当)
- Housing allowance (住宅手当), only when proportional to actual housing cost . Flat housing allowances are not excluded
- Temporary payments (臨時に支払われる賃金)
- Lump-sum payments paid less frequently than monthly (賞与, bonuses)
5. The April 2023 reform: 1.50× for SMBs too
Until March 2023, the elevated 1.50× rate for monthly overtime exceeding 60 hours applied only to large employers. The amendment to Article 37 effective April 1, 2023 extended the same threshold and the same elevated rate to small and medium-sized employers, closing the gap. There is no SMB carve-out in this calculator because none exists in current law.
6. Penalty for unpaid premium pay
Article 119 sets criminal penalties of up to 6 months imprisonment or a 300,000 yen fine per violation. Civil claims for unpaid premiums carry interest at the rate set in the wage payment guarantee statute (currently 14.6% per year), and the statute of limitations was extended in April 2020 from 2 years to 3 years for new claims, with a planned future extension to 5 years.
7. Edge cases worth knowing
- Management-level supervisors (管理監督者, Art. 41): exempt from the overtime, holiday and weekly limits, but still entitled to the 1.25× late-night premium for work between 22:00 and 05:00.
- Fixed overtime allowance (固定残業代 / みなし残業): permitted only if the contract clearly specifies the number of hours covered, the calculation base, and confirms that excess hours are paid at the full statutory rate. Without these elements the fixed allowance can be invalidated.
- Statutory vs company holidays: the 1.35× rate only applies to the legally required weekly rest day. Work on a non-statutory company holiday (e.g. Saturday in a Mon-Fri company) is treated as overtime if it exceeds the 40h/week limit.
- Variable working hours systems: under 1-month, 1-year and flex-time systems, the threshold for "statutory overtime" is computed differently (per the averaging period), but the premium rates themselves are unchanged.
Reference
Key terms and concepts
Premium pay (割増賃金)
The statutory uplift on the regular hourly wage that must be paid for overtime, late-night work, and holiday work under Article 37. The four base rates (1.25, 1.50, 1.25, 1.35) and their stacked combinations are mandatory minimums; work rules can be more generous but not less.
Statutory overtime (法定時間外労働)
Hours beyond the statutory 8 per day or 40 per week. These trigger the 1.25× premium and count toward the 36 Agreement caps. Overtime within the statutory limits but beyond the contractual schedule (所定時間外) is paid at ordinary rate unless the work rules say otherwise.
Late-night work (深夜労働)
Hours worked between 22:00 and 05:00. The 1.25× premium applies regardless of whether the work is also overtime. Late-night premium is the only premium that applies even to management-level supervisors who are otherwise exempt from the overtime regime.
Statutory holiday work (法定休日労働)
Work on the legally required weekly rest day under Article 35 (one full day per week, or four days every four weeks). Attracts the 1.35× premium. Holiday work is its own category and does not double-count as overtime.
Calculation base wage (算定基礎賃金)
The figure to which premium multipliers are applied. Equals the regular monthly wage minus the seven allowance categories enumerated in enforcement reg Art. 21 (family, commute, separated-family, education, rent-proportional housing, temporary payments, bonuses).
Monthly average scheduled hours (1か月平均所定労働時間)
Used as the denominator in the hourly base wage calculation. Standard formula: (365 − annual days off) ÷ 12 × hours per day. Some work rules use a fixed 160h or 173h; the calculator allows either approach via the override field.
Fixed overtime allowance (固定残業代 / みなし残業)
A pre-paid lump sum covering a defined number of overtime hours per month. Lawful only if the contract clearly specifies the hours covered and the calculation base, and confirms excess hours are paid at the full statutory rate. Otherwise it can be invalidated and the entire amount becomes part of the base wage.
Frequently asked
Common questions about overtime pay in Japan
Do all employers now have to pay 1.50× for over-60h overtime?
Yes. Since April 1, 2023, the elevated 1.50× rate for monthly overtime exceeding 60 hours applies to all employers regardless of size. Before that date it applied only to large enterprises.
What is the deadline to pay overtime owed?
Premium pay must be included in the next regular wage payment after the period in which the work was performed, in accordance with Article 24 (full-amount, on-time payment principle). Late payment can also attract delay interest.
Is part-time / baito staff entitled to the same premium rates?
Yes. Article 37 applies to all employees regardless of contract type. The hourly base wage computation differs (an hourly worker's wage is already an hourly rate), but the 1.25, 1.50, 1.25 and 1.35 multipliers and stacking rules are identical.
How do I calculate the base wage if there are commission payments?
Sales commissions and similar performance pay paid monthly are included in the base wage if they are part of the regular monthly compensation. Commissions paid quarterly or less frequently fall under the bonus exclusion and are excluded.
What if work spans midnight?
Each hour is classified by the time it was actually worked. Hours from 21:00 to 22:00 are not late-night; hours from 22:00 to 05:00 are. If the employee also passes the 8h/day or 40h/week threshold during that night, the late-night and overtime premiums stack to 1.50× (or 1.75× if the month total exceeds 60h).
How does this differ from contractual overtime?
Contractual overtime (所定時間外労働) is hours beyond the contractual schedule but within the statutory 8h/day and 40h/week limits. There is no statutory premium for these hours, only what your work rules say. This calculator covers statutory premiums only; check your work rules for any contractual uplift.
Can the employee choose paid leave (代替休暇) instead of the over-60h premium?
Yes, with a labor-management agreement, an employee can take substitute paid leave (代替休暇) in place of the additional 0.25× of the over-60h portion. The base 1.25× is still paid in cash; only the extra 0.25× can be exchanged for leave.
What if my company has a shorter work day (e.g. 7.5 hours)?
Hours between the contractual 7.5 and the statutory 8 per day are paid at the regular rate (no statutory premium), unless the work rules require a contractual premium. The 1.25× statutory premium kicks in only beyond the statutory 8/day or 40/week.
Important. This calculator implements the statutory minimum premium rates under Article 37 of the Labor Standards Act. It is provided for general information only and does not constitute legal advice. Industry-specific rules, company-specific work rules, fixed overtime allowance arrangements, and edge cases (variable working hours systems, flex-time, mid-period changes) may produce different results. Consult a licensed sharoshi (社会保険労務士) for binding answers.