What should this cost, and what's actually left over?

Why these five belong together

These aren't a random assortment — they're the arithmetic behind pricing and paying, in the order a business actually runs into it. Markup and profit margin cover the same relationship from two directions: what to charge given a cost, or what margin a price actually produces. Gross profit takes that single-sale math and scales it to a real period — a week, a quarter, a year — so it says something about total revenue instead of one transaction. CAGR steps outside pricing to answer a related but different question: how fast something grew, smoothed into one number, whether that something is revenue, a customer count, or an account balance. And time card is the input that funds all the others — the hours behind the labor cost that shows up as cost of goods sold on the gross profit page, turned into decimal hours and a paycheck.

Five separate questions, one underlying subject: what something costs, what to charge for it, what's left over, what it grew to, and what the hours add up to before any of the rest of it happens.

Each calculator page goes past the basic formula, too — the markup and profit margin pages untangle why those two numbers get confused so often, gross profit breaks down what actually counts as cost of goods sold, and CAGR explains why a smoothed growth rate isn't the same thing as averaging the yearly changes. None of that "why" is repeated here; it's on the page it belongs to.

How these work

Every calculator on this site runs entirely in the browser. Numbers you enter aren't sent to a server, stored, or shared — refresh the page and they're gone, because there's nowhere else for them to go. There are no accounts, no sign-up, and nothing to configure beyond the fields on the page itself.

Every formula is documented on its own calculator page, next to the tool that uses it — not in a separate reference section, and not behind a click-through. If a number looks unfamiliar, the explanation is right there with it. None of the five depend on a tax bracket, a jurisdiction, or a rate that changes underneath the page, so there's nothing here that goes stale on a schedule. Most of them also solve in more than one direction — enter a price and work back to the markup it implies, or enter a growth rate and work out how many years it takes to get there — so the same page answers the question however you're starting from it.