I built this after spending 20 minutes trying to figure out how much a £55,000 salary actually pays monthly in the UK — every calculator I found either wanted my email, showed me ads for financial advisers, or gave me a number I couldn’t trust. So I built one that just works. The UK side handles the stuff most calculators miss — the 60% tax trap between £100K-£125,140 where your Personal Allowance tapers, salary sacrifice pension impact, and the difference between your marginal rate (what you pay on the next pound) vs your effective rate (your actual overall burden). The US side covers all 50 states, both filing statuses, 401(k) deductions, and breaks FICA into Social Security and Medicare separately so you actually understand your payslip. Happy to answer any questions about how it works or what I’m building next on OneShekel.

oneshekel.com

Free UK & US income tax calculator.

Free UK & US income tax calculator.