Everyday Tools
Everyday tools for quick answers: work out percentages and discounts, calculate an exact age, check adult BMI, and create a QR code for a link or message.
All everyday tools
Quick answers to common questions
- What is 20% off $75? 75 × 0.8 = $60. Use “decrease by X%” in the percentage calculator.
- How many days old am I? The age calculator shows total days as well as years, months and days.
- What is a healthy BMI? For most adults, 18.5–24.9. See the BMI calculator for its limits.
- How do I share a link on a poster? Make a QR code and test it with two phones before printing.
What you can do here
- Percentage calculator: X% of a number, percentage change, and increase or decrease by a percentage.
- Age calculator: exact age in years, months and days, and days to your next birthday.
- BMI calculator: adult body mass index in metric or imperial units.
- QR code generator: a downloadable PNG QR code for any link or text.
Formulas shown, not hidden
Each calculator page explains the formula with a worked example, so you can check the answer yourself or repeat it in a spreadsheet.
Frequently asked questions
Yes. All LIVETOOLSLAB tools are free to use without an account.