About
A calculator that's actually nice to use
Pebble Calculator is a free, browser-based calculator built for everyday use. No app to install, no account required โ just open it and start calculating. It works entirely in your browser, so it's fast, private, and always available. Whether you're splitting a bill, solving a physics problem, or planning your mortgage, Pebble has a mode built for the task.
Most online calculators are either too basic to be useful or so cluttered with buttons they're intimidating. Pebble was built to sit squarely in between: genuinely capable, but calm and clear to look at. The name itself is a nod to the ancient origins of mathematics โ read the story behind the name.
Three calculator modes
Pebble gives you three distinct modes so you always have the right tool for the job. Switch between them instantly from the mode button โ no page reload, no setup.
Standard mode
Clean arithmetic for everyday calculations. Add, subtract, multiply, divide, percentages. The display is large and uncluttered, designed to be read at a glance. The history panel keeps a running log of your last calculations so you can refer back or tap any result to reuse it.
Scientific mode
Full scientific functions including trigonometry (sin, cos, tan), inverse trig, hyperbolic functions, natural and base-10 logarithms, powers, roots, factorial, and the constants ฯ and โฏ. Supports both degree and radian modes. The layout expands cleanly on larger screens and stays usable on mobile.
Financial mode (TVM)
A Time Value of Money calculator for loans, mortgages, savings, and investment planning. Solve for any one of five variables: N (periods), I/Y (interest rate), PV (present value), PMT (payment), or FV (future value). Supports Begin and End period switching for annuity-due calculations. See the guides below for worked examples using real loan and savings scenarios.
All features
- Three calculator modes โ Standard, Scientific, and Financial (TVM)
- Six earthy color themes โ from warm clay to deep forest green
- Calculation history with one-tap result restore
- Copy result to clipboard in one click
- Optional typing sound effects with adjustable volume
- Button shape picker โ Square, Soft, Round, or Circle
- Six font choices including Serif, Rounded, and Geometric
- Full keyboard support for fast input
- All preferences saved locally โ your settings persist across visits
- Works offline โ no internet connection required after first load
- No account, no login, no tracking of personal data
Who it's for
Pebble is for anyone who wants a calculator that looks good and works well. Students use the scientific mode for homework and exams. Finance professionals and home buyers use the financial TVM mode to model loans and savings scenarios. Everyone else just wants something quick and clean for everyday arithmetic.
If you've ever found standard calculator apps cold and clinical, Pebble was designed with you in mind. The warm earthy tones, soft typography, and thoughtful layout make it a tool you'll actually enjoy opening. There are no ads interrupting the calculator itself, no popups asking for notifications, and no dark patterns nudging you to install an app.
The financial guides are particularly useful for anyone navigating a major money decision. See how to calculate a mortgage payment, model student loan repayment, understand compound interest, or find your FIRE number for financial independence.
Privacy
No personal data is collected or transmitted. All your calculations and preferences are stored locally in your browser's storage โ they never leave your device. The calculator itself has no server-side component. Display ads are served by Google AdSense; see the Privacy Policy for details on what cookies those ads set.
Questions or feedback?
We'd love to hear from you โ whether it's a bug report, a feature idea, or just a note to say hello. Head to the Contact page to get in touch.
Frequently asked questions
Is Pebble Calculator completely free?
Yes, Pebble is free with no hidden costs, subscriptions, or premium tiers. All three calculator modes โ Standard, Scientific, and Financial โ are available to everyone without any account or sign-up.
Does Pebble work on mobile?
Yes. Pebble is fully responsive and designed to work well on phones, tablets, and desktops. The layout adapts to your screen size so the buttons remain easy to tap on smaller displays.
Do I need to install anything?
No installation required. Pebble runs entirely in your web browser โ just open the page and start calculating. It works in Chrome, Firefox, Safari, Edge, and any modern browser.
What is Financial mode and how is it different from Standard?
Financial mode is a Time Value of Money (TVM) calculator โ the same type used on a BA II Plus financial calculator. It lets you solve for loan payments, savings goals, mortgage costs, and investment growth by entering four of five variables and computing the fifth. Standard mode is for everyday arithmetic.
Are my calculations saved?
Your recent calculations appear in the history panel and are saved in your browser's local storage. They persist between sessions on the same device and browser, but are never sent to any server. Clearing your browser data will remove them.
Can I use Pebble offline?
After your first visit, Pebble's assets are cached by your browser, so it will continue to work even without an internet connection. The calculator itself has no server-side logic โ all computation happens locally.