About CalcHandy
CalcHandy is a free collection of online calculators for the everyday questions that come up around the house, at work and when you sell things online. How much gravel should I order? What will this overtime week pay? How much of a $50 sale does the marketplace keep? Each of these has an answer you can work out with arithmetic, but most people do not want to rebuild the formula every time. CalcHandy does it for you and shows its work.
What you will find here
- Home & DIY: gravel, mulch, deck stain, BTU, wire gauge and generator size calculators that turn the size of a space into the amount of material or capacity you need.
- Pay & Work: overtime, PTO accrual, shift differential, tip pool and no-tax-on-tips calculators that show how a paycheck or deduction is built.
- Seller Fees: Etsy, Stripe, Venmo and TikTok Shop fee calculators that show what a platform takes and what you keep.
- Pets: a puppy weight calculator that estimates adult size, with more pet tools planned.
Why we built it
Many calculator sites give you a number with no explanation, bury the tool under ads, or ask for an email address first. We wanted the opposite: the answer at the top of the page, the formula underneath, and plain-language notes on the mistakes that cost people money. If you can see how a number was produced, you can decide whether to trust it for your own situation.
How we keep results accurate
Every formula lives in its own small piece of code with automated tests that check it against answers worked out by hand. Where a tool depends on an outside standard, such as the National Electrical Code ampacity table or IRS guidance on the tips deduction, we use the published source and link to it. Fee calculators show the date we last checked the platform's official rates, because marketplaces change pricing often. You can read the full process on our How We Calculate page.
What our calculators are not
Our tools give estimates for general information. They are not financial, tax, legal, electrical, veterinary or other professional advice. A calculator cannot see your local building code, your employer's exact payroll rules or your pet's health history. Treat the result as a well-explained starting point and confirm anything important with the official source or a qualified professional. See our Disclaimer for details.
How the site is funded
CalcHandy is free to use. We may show advertising to cover hosting and the time it takes to build and check each tool. Ads are kept clear of the calculator itself, and they never change the results. Our Privacy Policy explains what data advertising partners may collect and how you can control it.
Our principles
- Show the work. Every result comes with its formula and a worked example so you can check it yourself.
- Use real sources. We follow published standards and official fee pages, and we say when something is an estimate or a rule of thumb.
- Keep it fast and private. The tools run in your browser. We do not ask you to sign up, and the numbers you enter are not sent to us.
- Be honest about limits. We list when an answer changes and when you should ask a professional.
- Fix mistakes openly. Material corrections are listed on our How We Calculate page.
Corrections and suggestions
If you find a wrong number, an outdated fee or a confusing explanation, please tell us on the contact page. We review every report, fix confirmed errors quickly and update the page's "last updated" date. We also add new calculators based on what people ask for, so tell us what you need.