FAQ
Questions about the site itself — accounts, data, accuracy, and which calculator to use. For the arithmetic behind a specific result, each calculator page has its own FAQ section.
Common questions
Are these free? Do I need an account?
Free, and there's nothing to sign up for. Every calculator on this site works without an account — open the page, enter numbers, get an answer.
Is anything I type sent anywhere?
No. Every calculator runs entirely in your browser — the numbers you enter are never sent to a server, stored, or shared. Close the tab and they're gone. See the privacy policy for the full detail.
How accurate are these? Where do the formulas come from?
Each calculator uses a standard, well-established formula for its subject — markup, margin, gross profit, CAGR, and payroll-hours arithmetic aren't something this site derived. The formula and its assumptions are documented on the page that uses it. These are pure arithmetic tools: there's no tax data, no jurisdiction rules, and no rate table behind any of them to verify against a government source. The answer is only as good as the numbers you put in.
Why don't these handle tax?
Deliberately left out. These are currency-agnostic business arithmetic — markup, margin, profit, growth, hours — and none of that changes with the tax year. Adding tax would mean state-by-state rules and a maintenance schedule to keep them current, which isn't what this site is built to do. See the disclaimer for more on what these calculators are and aren't.
Can I use these for my business books or payroll?
They're estimates for general information, not a system of record. The time card calculator, for example, adds up hours from what you enter — it's not a timekeeping or payroll system, and it doesn't apply any state's overtime rule automatically. Verify a figure before relying on it for an actual business or payroll decision. See the disclaimer.
Which calculator should I use?
- Markup Calculator — pricing an item from what it costs.
- Profit Margin Calculator — checking what margin a price actually produces.
- Gross Profit Calculator — the profit behind a period of revenue.
- CAGR Calculator — the growth rate between two values.
- Time Card Calculator — a week of hours and pay.
Do you have a Canadian version?
Yes — calc-hq.ca covers Canadian payroll and tax: take-home pay, CPP, EI, and provincial calculators built on CRA and Service Canada figures. This site, calc-hq.com, is separate — pure business arithmetic, no tax data, U.S.-facing.