Methodology & Data Sources

Data Sources

PlainGlobalPay draws from five international and research datasets to compute take-home pay comparisons across OECD economies:

  • OECD Taxing Wages 2024 — The official source for income tax rates and employee social security contributions at multiple salary levels across all 38 OECD member countries. Published annually by the OECD Centre for Tax Policy and Administration.
  • World Bank International Comparison Program (ICP) — Purchasing Power Parity (PPP) conversion factors for household final consumption expenditure. Worldwide statistical initiative coordinated by the World Bank with participation from over 170 economies.
  • OECD Average Wages dataset — National average annual wages in PPP-adjusted USD for each OECD member.
  • Tax Foundation — Statutory corporate and personal income tax rates, VAT and sales tax rates, and tax policy analysis for OECD countries.
  • OECD BEPS monitoring — Pillar Two global minimum tax (GloBE rules) implementation status by country.
  • IMF Working Papers — Independent comparative analysis of tax wedge methodology and effective rates.

Coverage

PlainGlobalPay covers 38 OECD member countries with pre-computed take-home pay scenarios for 3 family types (single earner, single earner with two children, and dual earner) and 29 salary levels ranging from entry-level to executive compensation. This produces over 3,000 unique take-home calculations, each showing gross salary, income tax, social security contributions, net pay, and PPP-adjusted purchasing power.

Processing Pipeline

  1. OECD Taxing Wages benchmark data is extracted for all 38 member countries at three reference salary levels: 67%, 100%, and 167% of the national average wage.
  2. Tax Foundation statutory rate data is compiled for each country, including top marginal income tax rates and standard social security contribution rates.
  3. World Bank PPP conversion factors for household final consumption are downloaded and aligned with the OECD country set.
  4. For each country, tax calculations are interpolated across 29 salary levels using the methodology described below, producing gross-to-net breakdowns for each family type.
  5. PPP adjustments are applied to net pay figures, converting nominal take-home amounts into purchasing-power-equivalent dollars for cross-country comparison.
  6. Country comparison pairs are pre-computed for all 703 two-country combinations, enabling instant side-by-side salary analysis.
  7. All data is loaded into a structured SQLite database serving country profiles, salary calculators, comparison pages, and ranking tables.

Tax Rate Interpolation

OECD Taxing Wages publishes detailed tax calculations at benchmark salary levels (67%, 100%, and 167% of the national average wage). For intermediate salary levels between these benchmarks, PlainGlobalPay interpolates using linear interpolation between the nearest data points. For salaries above 167% of average wage, the statutory top marginal rate is applied with conservative adjustments to reflect bracket threshold effects and phase-outs.

Employee social security contributions are applied as published by the OECD, including any earnings ceilings that cap contributions at higher income levels. Employer-side social security contributions are tracked separately and are not included in the employee take-home calculation unless specifically relevant to the country's system.

PPP Adjustments

All PPP conversions use World Bank household final consumption PPP factors, which are the most appropriate measure for comparing individual living standards across countries. Unlike GDP-based PPP (which includes government spending and investment) or producer-price PPP, household consumption PPP reflects the actual prices that individuals pay for goods and services. This allows meaningful comparison of real purchasing power across countries with very different price levels — a $60,000 salary in Switzerland and a $30,000 salary in Poland may provide similar living standards once PPP is applied.

Accuracy Commitment

PlainGlobalPay uses published OECD and World Bank data as its foundation, with transparent interpolation for salary levels between published benchmarks. The interpolation methodology is documented above and applied consistently across all countries. When OECD Taxing Wages releases updated annual data, PlainGlobalPay refreshes all calculations to reflect the new figures.

Limitations

  • Tax rates are based on OECD standardized household scenarios and may not reflect individual situations that involve itemized deductions, tax credits, or subnational and local taxes not captured in the OECD framework.
  • PPP adjustments reflect national averages and may not accurately represent conditions in specific cities or regions — living costs in London differ substantially from rural England, for example.
  • Tax laws change frequently across OECD countries. Figures reflect the 2024 OECD Taxing Wages publication year and may not capture subsequent legislative changes.
  • PlainGlobalPay is not affiliated with the OECD, World Bank, Tax Foundation, or any government agency. This site is for informational purposes only and should not be used for tax compliance. Consult a qualified international tax professional for personal advice.

Contact

Questions about our methodology? Contact us.