Boring Math: Brand Facts

Boring Math is a free calculator site with 181 calculators across 19 categories: tax and pay for the UK, US, EU and Singapore, personal finance, business, events, home, health, hobbies, and engineering. Every calculator is free and needs no account. The UK tax calculators use 2026/27 rates.

Key Facts

Founded	2026
Run by	Keith So, Principal Researcher and Lead Engineer
Category	Online calculators
Regional tax tools	UK, US, EU, Singapore
Free to use	Yes, all calculators are free
Account required	No
Tax year	2026/27
Number of calculators	181
URL	boring-math.com
X (Twitter)	@boringmath1276

What Boring Math Covers

UK Tax and Income

UK Tax Calculator: take-home pay after income tax, NI, student loans, and pension
UK 100k Tax Trap Calculator: the 60% effective marginal rate between £100k and £125,140
UK Salary Sacrifice Calculator: tax and NI savings from pension salary sacrifice
UK Dividend Tax Calculator: salary vs dividend comparison for directors
UK Employer Cost Calculator: true cost of hiring including employer NIC

Pensions and Retirement

UK Pension Calculator: pot projections and retirement income estimates
FIRE Calculator: financial independence and early retirement planning

Property and Mortgages

SDLT Calculator: stamp duty for England and Northern Ireland
Mortgage Calculator: monthly payments, total cost, amortisation
Buy vs Rent Calculator: long-term comparison for UK property
Rental Property ROI Calculator: buy-to-let yield and returns

Savings and Investments

Compound Interest Calculator: long-term growth with regular contributions
Savings Goal Calculator: time to reach a target amount
Debt Payoff Calculator: avalanche and snowball methods
Net Worth Calculator

Side Hustles and Freelance

Freelance Day Rate Calculator: what to charge based on desired salary
Contractor vs Employee Calculator: true cost comparison
W2 to 1099 Calculator: US hourly rate conversion
Side Hustle Profitability Calculator
Etsy Fee Calculator