Time zones and browser implementation
- IANA Time Zone Database — time-zone identifiers used by software systems.
- MDN: Intl.DateTimeFormat — browser API used to format selected local times.
Personal tax and payroll
Tax and payroll rules vary by country, residence, tax year, and personal circumstances. CleanPercent does not use a tax table. Use the relevant tax authority, payroll provider, or qualified adviser for an official calculation. For Sweden, start with the Swedish Tax Agency.
Investing and trading education
Return and trade calculators explain formulas from values entered by a visitor. They do not use live market data, make forecasts, or recommend investment or trading activity. For general investor education, see Investor.gov. For futures terminology and the meaning of contract size, see the CFTC glossary. The SEC’s Day Trading: Your Dollars at Risk explains that day trading can be highly risky and that real costs and losses matter. Review the terms, costs, and risks of any product or platform independently.
Manual futures starter presets
The calculator’s futures dropdown is a static educational starter list, checked on 2 October 2026. It includes selected CME products and their contract units: E-mini S&P 500 ($50 × index), E-mini Nasdaq-100 ($20 × index), Micro Gold (10 troy ounces), and Micro WTI Crude Oil (100 barrels). Micro index multipliers are shown as a smaller version of the named E-mini contract. These are not live specifications; visitors must verify the relevant current exchange or broker information.
How sources are used
Source links support stated methods and help readers verify technical concepts. They do not turn a generic calculation into tailored advice. Contact us if a reference becomes outdated or unclear.