Free tools for people
who fix things themselves

Why DIY9lives exists

I'm the person who fixes whatever breaks — a car, a washing machine, a sink, the house, a computer. Along the way I kept Googling the same small calculators and running into login walls, email gates, or a monthly subscription for what is basically arithmetic.

So I started building my own versions. Friends began asking for tools too, and DIY9lives grew from there: practical calculators and converters for money, cars, home projects, health, cooking, writing, and everyday life.

What you'll find here

Dozens of free tools, with more added regularly — from a mortgage calculator and a tire size calculator to a concrete calculator, a recipe scaler, and a VIN decoder. Everything is free to use with no account and no email required.

How the tools work

Almost every calculation runs right in your browser, so what you type isn't sent to us or stored anywhere. A few tools do reach out to a public service to do their job (for example, the VIN decoder looks up vehicle specs from the U.S. NHTSA database, and the currency converter pulls daily exchange rates). The Privacy Policy spells this out.

Where the numbers come from

• Tire and wheel math uses standard industry formulas for sidewall height, diameter, and speedometer error.
• State sales tax rates in the car price calculator come from the Tax Foundation's published state rates.
• VIN decoding uses the free NHTSA vPIC public database.
• Exchange rates come from the Frankfurter API, which publishes reference rates.
• Tax and finance tools use simplified federal brackets and assumptions. Each tool notes what it assumes, because real life is messier than a calculator.

These are estimates built to help you plan, not to replace a professional. See the Terms & Disclaimer for the details.

How the site is funded

The site is free to use and supported by advertising, which helps cover the domain and hosting. I don't sell your data, and the tools won't ever ask you to pay to see an answer.

Help shape what gets built next

Missing a tool? Found a bug? Something confusing? Tell me here or email diy9lives@gmail.com. Most of what's on this site started as somebody's request.