Sources
The official primary source used for every country’s calculators on this site.
Every rate, threshold and formula on this site is built from the specific legislation or official guidance below. Where a country has multiple regional or jurisdictional sources (such as Canada’s provinces or US states), the primary national or federal source is listed first, with jurisdiction-specific notes on the relevant calculator page itself.
United Kingdom
Australia
- Fair Work Ombudsman — leave
- Fair Work Act 2009
- State and territory Long Service Leave Acts
Canada
- Ontario.ca — Employment Standards Act guide (worked-example jurisdiction)
- Provincial and territorial employment standards legislation (14 jurisdictions)
- Canada Labour Code (federally regulated employers)
- Canada.ca — EI maternity and parental benefits
United States
- U.S. Department of Labor — Wage and Hour Division
- Fair Labor Standards Act; Family and Medical Leave Act
- State labor department guidance (varies by state)
New Zealand
- Employment New Zealand — leave and holidays
- Holidays Act 2003 (current law)
- Employment Leave Act 2026 guidance (commences 6 August 2028)
- Inland Revenue (Paid Parental Leave)
Ireland
- Workplace Relations Commission — leave
- Organisation of Working Time Act 1997
- Sick Leave Act 2022
- Department of Social Protection (Maternity, Parent’s and Paternity Benefit)
How sources are used
Figures are taken directly from official guidance and legislation, not from third-party summaries or other calculator sites. Where official guidance is genuinely ambiguous or where reasonable professional interpretations differ, the calculator’s “what this doesn’t cover” section says so rather than presenting one interpretation as definitive.