About QuickCalc

QuickCalc is a small, independent website run by Johannes Nieuwboer, an individual maker based in the Netherlands. It started from a simple frustration: everyday sums — a tip, a discount, VAT on an invoice, what a yearly salary means per hour — are easy to get wrong, and many calculator sites bury the answer under pop-ups, sign-up walls or unclear formulas.

What you'll find here

• 32 free calculators and converters for money, health, home, time and work.
• A dedicated page per calculator that shows the formula, a worked example, a quick-reference table and answers to common questions.
• In-depth guides that explain the ideas behind the numbers, such as compound interest or gross vs. net pay.
• Versions in English, Dutch, Spanish, French, German, Russian and Chinese.

How we work

Every calculator runs entirely in your browser: the numbers you type are not sent to a server or stored. Formulas are the standard ones used in finance, health and unit conversion, and each page states which formula is used so you can check it yourself. Country-specific facts, such as VAT rates or tipping customs, are described as general guidance — rules change, so always confirm important tax, legal or medical figures with a qualified professional.

How the site is funded

QuickCalc is free to use and is supported by advertising. Visitors who prefer no ads can buy QuickCalc Pro, a one-time $4.99 upgrade that removes ads and adds saved calculation history. Payments are handled by Paddle as merchant of record.

Get in touch

Spotted a mistake, missing a calculator, or have a suggestion? Send a message through the contact page — every message is read.