Every FinCalcHub tool for understanding what you actually keep — salary after tax, PAYE, NI, FICA, UIF, and the tax-advantaged accounts (401(k), ISA, TFSA, Roth IRA) that change the answer. Free, instant, no signup.
For most working people, tax is the single largest line in their budget — bigger than housing, food and transport combined — yet it's the one most people understand the least well. Five categories of tax show up across the USA, UK and South Africa, and any serious personal-finance plan has to handle each of them. Income tax is the headline charge on your earnings, applied via tax brackets that increase as income rises. Social security contributions — National Insurance in the UK, FICA in the US, UIF in South Africa — fund state pensions and unemployment insurance, and behave like additional flat-rate income tax for budgeting purposes.
Beyond income, three more taxes shape big financial decisions. Capital gains tax applies when you sell investments or property at a profit; the rate is usually lower than your income tax rate, and there's normally an annual tax-free allowance. Dividend tax applies to distributions from shares — UK has a small annual dividend allowance, the US taxes qualified dividends at long-term capital-gains rates, and SA has a flat 20% dividend withholding tax. Inheritance and estate taxes only matter at higher net worths but are often the biggest single tax event a family ever pays. A serious tax-aware plan touches all five.
Tax rules differ enough by country that a calculator built for one region gives a misleading answer in another. FinCalcHub's tax tools are built for all three.
American income tax is the most complex of the three because it stacks federal, state and sometimes city rates. Federal brackets run from 10% to 37% in seven steps, with separate single, married-filing-jointly and head-of-household tables. State income tax ranges from 0% (e.g. Texas, Florida, Tennessee) to over 13% top rate (California). FICA is 7.65% on wages up to the Social Security cap — 6.2% Social Security and 1.45% Medicare, with an extra 0.9% Medicare on high earners. The standard deduction is large enough that most households no longer itemise.
UK income tax is more compact. There's a £12,570 personal allowance, then 20% basic rate up to £50,270, 40% higher rate up to £125,140, and 45% additional rate above that. The personal allowance tapers to zero between £100,000 and £125,140, creating a 60% effective marginal band that's worth planning around. National Insurance is paid by employees at 8% on the same earnings bracket as basic-rate income tax, plus 2% above. PAYE deducts both monthly via the employer.
SA income tax runs from 18% to 45% across seven brackets, with primary, secondary (age 65+) and tertiary (age 75+) rebates that effectively raise the tax-free threshold. UIF is 1% from the employee and 1% from the employer on income up to a monthly cap (currently R17,712), funding unemployment and maternity benefits. There's also a Skills Development Levy paid by the employer. SARS PAYE is deducted cumulatively, so monthly take-home varies as you move through brackets across the tax year.
The single biggest tax decision most savers make isn't which deductions to claim — it's which wrapper they put their long-term money into. Tax-advantaged accounts compound your money without the annual drag from dividend and capital gains tax, and many of them shield the final withdrawals as well. Over a 30-year horizon, this typically doubles the final pot compared to the same money in a taxable brokerage account.
There are two flavours. Tax-deferred wrappers (401(k), Traditional IRA, SIPP, RA) give you a deduction now and tax the withdrawals in retirement — useful when you expect to be in a lower tax band later. Tax-free wrappers (Roth IRA, ISA, TFSA) take post-tax money but never tax the growth or the withdrawals — useful when you expect rates to rise or when you want flexibility in retirement. A balanced plan usually combines both, and the relative emphasis depends on your current marginal rate, the country's annual limits, and how much you can afford to put in. The tax-wrapper calculators on FinCalcHub model each one with the current year's contribution limits enforced.
The biggest tax misconception in personal finance is the belief that a raise can push your whole salary into a higher bracket. It can't — brackets only apply to the portion of income inside them. Your marginal rate is the tax on the next pound, dollar or rand you earn. Your effective rate is total tax divided by total income, and it's always lower than your marginal rate because the brackets below yours are taxed at lower rates. A UK salary of £60,000 has a 40% marginal rate but pays roughly £11,400 in income tax — an 18% effective rate.
This matters for three real decisions. First, pension contributions: a higher-rate UK taxpayer gets 40% tax relief on every pound salary-sacrificed, but only avoids tax on the portion above £50,270. Second, bonuses: the marginal rate on a bonus is what matters, not the effective rate — a US bonus is often withheld at a flat 22% but reconciled at marginal at year-end. Third, Roth vs Traditional: you compare your current marginal rate against your projected retirement marginal rate, not your average rate. Get this distinction right and the rest of tax-aware planning gets a lot simpler.
Run the actual numbers for your salary, bonus or tax-wrapper choice. All calculators support USA, UK and South Africa where relevant.
Your marginal rate is the tax on your next dollar / pound / rand of income — the rate of the bracket you're currently in. Your effective rate is total tax divided by total income — always lower than your marginal rate because the brackets below yours are taxed at lower rates. A salary of £60,000 in the UK has a 40% marginal rate but an effective income tax rate of around 18%.
Take-home pay is gross salary minus income tax, social security contributions (NI / FICA / UIF) and any pre-tax deductions (pension, HSA, salary sacrifice). Each country layers them differently. The take-home pay calculator handles all three with current-year rates.
Yes — over a 30-year horizon they often double the final pot compared to the same money in a taxable brokerage account. Inside a 401(k), ISA, TFSA or Roth IRA you avoid drag from annual tax on dividends and capital gains, plus you sidestep tax on the final pot itself. A 1% annual tax drag compounded over 30 years is roughly a 26% smaller final balance.
Bonuses are taxed at your marginal rate. In the UK that's typically 20%, 40% or 45%. In SA, marginal rates run from 18% to 45%. In the US, bonuses are usually withheld at a flat 22% federal rate but are reconciled against your marginal rate at year-end.
Most discrepancies come from pre-tax deductions the calculator doesn't see — pension contributions, salary sacrifice, healthcare, student loan repayments, or in the US, state-specific items. PAYE in the UK and SA is also calculated cumulatively over the year, so individual months can be higher or lower than 1/12 of the annual figure.
Tax sits underneath every other financial decision. Choosing the right wrapper directly affects how much you can save for retirement; understanding marginal rates affects whether you should overpay your mortgage or invest.
Deeper reads: Salary after tax · UK National Insurance · UK Personal Allowance · South Africa tax guide · What is PAYE in South Africa? · Tax on R500,000 in SA · 401(k) and your paycheck