About Zerdly
Zerdly is a growing collection of free calculators, converters and file tools that run entirely in your web browser.
We’re building a single, reliable home for the everyday maths and conversions people actually need — for work on site, study, projects around the house and quick calculations on the go. From concrete volumes and Ohm’s law to loan repayments, BMI, coordinate conversions and PDF tools, the goal is simple: get an accurate answer quickly, without fuss.
Everything on Zerdly runs locally in your browser. That means your numbers, files and results never leave your device — there are no accounts, no uploads and nothing stored on a server. It also keeps the tools fast and lets most of them work even when you’re offline.
Free & fast
Every tool is free to use with no sign-up. Pages are lightweight and load instantly.
Private by design
Your inputs, files and results stay on your device — nothing is uploaded or stored on a server.
Works offline
Because the maths runs in your browser, most tools keep working even without a connection.
Built to be useful
Clear results, worked examples and full precision — made for tradespeople, students and professionals.
We’re in beta
Zerdly is still getting things rolling — we’re actively adding tools, polishing the details and listening to feedback. If something looks off, or there’s a calculator you’d like us to build, we’d love to hear from you.
Zerdly is a registered business name. For privacy details see our Privacy Policy, or reach us any time at contact@zerdly.com.