About CalcMoose

CalcMoose is a free collection of everyday calculators: pay and work hours, home-improvement materials, dates and ages, school grades, and a few health and pet tools. Every page works on a phone, needs no sign-up, and shows how the number was worked out.

How we build calculators

• Your inputs stay on your device. Calculations run in your browser; the numbers you type are not sent to our server.
• Official sources first. Where a rule comes from a government agency or a manufacturer (for example the CDC for BMI ranges or the U.S. Department of Labor for overtime), we link to it and show the date we last reviewed it.
• Formulas are shown. Each calculator explains the formula and assumptions so you can check the result yourself.

Limits

Results are estimates for general information. They are not financial, legal, medical or engineering advice. For decisions that matter (pay disputes, structural work, health), check with a qualified professional.

Found a mistake or want a new calculator? Let us know.