Payday.is Salary Calculator (Laun)

Icelandic take-home salary calculator via payday.is public API.

API

• Endpoint: POST https://payday.is/is/ajax/calculator/calculateSalary/
• Auth: None (public XHR, requires X-Requested-With: XMLHttpRequest)
• Format: JSON request/response

Input Modes

1. Gross salary — set Salary, leave TotalCost null
2. Employer total cost — set TotalCost, leave Salary null

2025 Default Rates

Parameter	Default	Description
PensionContributionEmployeePercentage	4.00%	Mandatory employee pension
PensionContributionEmployerPercentage	11.50%	Mandatory employer pension
RehabilitationFundPercentage	0.10%	Starfsendurhæfingarsjóður
IncomeTaxStep1Percentage	31.49%	Up to ~446,136/mo
IncomeTaxStep2Percentage	37.99%	446,136–1,252,501/mo
IncomeTaxStep3Percentage	46.29%	Above 1,252,501/mo
InsuranceFeePercentage	6.35%	Tryggingagjald (employer)
PersonalTaxAllowancePercentage	100%	Persónuafsláttur (72,492 kr/mo in 2025)

Usage

# Monthly gross -> take-home
uv run python scripts/laun.py 1000000

# From employer total cost
uv run python scripts/laun.py 1200000 --total-cost

# With union fee
uv run python scripts/laun.py 750000 --union 1.1

# Full JSON breakdown
uv run python scripts/laun.py 1000000 --json

# Additional voluntary pension (viðbótarlífeyrissparnaður)
uv run python scripts/laun.py 1000000 --additional-pension 4.0

Response Fields

Key fields in the JSON response data:

• salary — gross monthly salary
• totalCost — total employer cost
• payoutAmountSalary — take-home pay
• incomeTaxEmployeeTotalAmount — total income tax
• pensionContributionEmployeeTotalAmount — employee pension
• personalTaxAllowanceAmount — tax credit applied

Caveats

• Tax rates change yearly — defaults are 2025 rates baked into payday.is
• Union fee varies by union (typically 0.7–1.25%)
• Does not account for benefits in kind, car allowance, etc.
• Personal tax allowance is per-person; couples can transfer unused allowance via SpouseTaxAllowancePercentage