Pay: the hourly rate is only half the story
The hourly wage calculator turns a rate into weekly, monthly and yearly figures, and takes off the deductions that actually apply where you work. It asks for your region first, and that order is deliberate.
Paid holiday is a legal floor in some places and nowhere in others
In the United Kingdom every worker is entitled to 5.6 weeks of paid holiday a year. For irregular-hours and zero-hours staff that becomes an accrual rate: take 5.6 weeks out of 52 and 46.4 working weeks remain, so 5.6 ÷ 46.4 gives 12.07%. Every hour worked earns 12.07% of an hour of paid leave.
In the United States federal law requires no paid vacation, no paid holidays and no paid sick leave for private-sector workers. Plenty of employers offer time off, but as a benefit rather than a floor. The same hourly rate therefore produces meaningfully different annual pay on the two sides of the Atlantic, and any calculator that ignores the difference will hand you a confident wrong answer.
The EU sets a shared floor of four weeks and then fragments — six member states have no statutory minimum wage at all and rely on collective agreements instead, which is why the calculator asks you to enter your own contribution rate rather than pretending one number fits.
FICA is not a flat 7.65%
Social Security takes 6.2%, but only up to the $184,500 wage base — above that it stops entirely. Medicare takes 1.45% with no cap, and an Additional Medicare 0.9% lands on wages over $200,000. Overtime counts as wages for all three, and federal law requires it at one and a half times the regular rate beyond 40 hours in a week. Income tax depends on your filing status and withholding choices, so the calculator leaves it out rather than guessing.
Gold: the weight unit changes the price
The gold price calculator quotes gold, silver and platinum in the unit your market actually uses. That matters more than it sounds, because two units in common use share a name and differ by a third.
Ounce, tola, tael
London and New York trade in troy ounces of 31.1034768 g. The ordinary ounce used for food is 28.35 g — about 10% lighter, and mixing the two is expensive. Across South Asia the unit is the tola, 11.6638 g, defined as exactly three eighths of a troy ounce, which is why ten tola is 116.638 g rather than a tidy 116.
The tael is where most errors happen. Hong Kong's bullion tael is 37.429 g — exactly 1.2 troy ounces, fixed by the Weights and Measures Ordinance of 1885 and still the standard for licensed members of the Chinese Gold and Silver Exchange Society. The mainland Chinese 市兩 is 50 g. A price quoted "per tael" is ambiguous until you know which one, and the gap is a third of the value.
Purity, and the round trip
Karat and millesimal fineness say the same thing from opposite ends: 24K is 999, 22K is 916, 18K is 750, and 9K/375 is the lowest grade the UK allows to be called gold. Where you see a three-digit stamp, it is parts per thousand.
The part people miss is that gold can hold its value exactly and still lose you money. Buying adds a making charge or premium — small on bars, often 10–25% on worked jewellery — plus any sales tax. Selling subtracts refining costs and the dealer's margin, and the tax is generally not refunded. The spread between a dealer's sell price and buy-back price commonly runs 15–20%. That is how far the metal price has to rise before you break even, and the calculator shows the figure directly.
Currency: mid-market is not what you pay
The currency converter carries every currency in the rate feed — over 160 — rather than the two or three dozen with the highest search volume. Every rate is quoted against the US dollar, so a rate between two other currencies is one divided by the other. If a dollar buys 474.7 tenge and 65.7 afghani, then one tenge is 65.7 ÷ 474.7 = 0.1384 afghani. Doing that in one step avoids two lookups and two roundings.
One consequence is worth knowing: a cross rate inherits the error of both legs. For heavily traded pairs that is negligible. For two thin currencies the mid-market cross can sit some distance from anything you could actually transact at, because there may be no direct market between them.
And the rate shown is the midpoint of the wholesale market, which no retail customer is offered. Card payments abroad come closest, roughly 1% away once network and issuer margins are counted — decline the "pay in your home currency" offer at the terminal, because dynamic currency conversion is consistently worse. Bank transfers add a spread plus a fixed fee, which bites hardest on small amounts. Cash counters are widest of all, and airport counters are the worst almost everywhere.
What none of these do
Rates here are fetched once a day when the site is rebuilt and written straight into the page, so they are a daily reference, not a live feed. None of the three applies your provider's fees, your local sales tax or your income tax band, because those depend on who you are dealing with. For anything large or time-sensitive, confirm with whoever is actually executing it — your payslip, your dealer, your bank.