Callie opens to the calculator because that is where most everyday math begins. Basic and Scientific modes stay close without making the app feel crowded.
Callie 2.0 is live
Everyday math, beautifully organized.
Callie is an all-in-one calculator and utility workspace for iPhone, iPad, Android phones, and Android tablets. Use one calm app for quick calculations, scientific mode, tips, bill splitting, currency conversion, unit conversion, percentages, date math, and practical money tools.
Now live on iOS and Android · Fresh daily currency rates · 32 languages · Basic + Scientific calculator · Money tools · Unit conversion · Date math
Callie 2.0
The first major Callie update is here.
Callie has grown past 2,000 users, with more people finding it every day. Version 2.0 is the first major update: a cleaner dark glass interface, a more intuitive workspace, smoother movement between tools, a new Currency Converter, and expanded support for 32 languages.
The goal is still simple: one calm place for the everyday math that shows up in real life.
What Callie helps with
What Callie helps with
Callie covers the everyday math and utility work people actually do: quick totals, scientific checks, currency conversion, unit conversion, percentages, dates, and practical money helpers.
Calculator
Start with a clean everyday calculator, then switch into Scientific mode when the problem needs more.
Learn more CurrencyConvert 169 currencies with fresh daily Frankfurter exchange-rate data, common currency shortcuts, search, swap, and cached rates after your first update.
Learn more MoneyCalculate tips, split bills, estimate tax and discounts, compare unit prices, estimate fuel costs, and check simple loan payments.
Learn more ConvertConvert length, weight, temperature, and volume. Use Percentage Helper for percent-of, what-percent, and percentage-change questions.
Learn more DatesCount days, compare dates, add offsets, and check age differences without opening another app.
Learn more LanguagesUse Callie in 32 supported languages, with in-app language selection and broader international support across iOS and Android.
Learn more
Why people keep Callie installed
Why people keep Callie installed
Callie earns its place by keeping the small math moments of real life together. It is not trying to be a banking app, a spreadsheet, or a complicated finance platform. It is built for the quick checks people actually repeat: totals, tips, rates, dates, units, percentages, and scientific math when needed.
Tips, bill splitting, sales tax, discounts, unit price, fuel cost, loan payment, and currency conversion live in one calm Money workspace.
Unit Converter and Percentage Helper keep measurement and percentage checks beside the rest of your math.
Date Calculator and Age Difference make timelines, deadlines, and date spans easier to check.
Callie 2.0 supports 32 languages because everyday math should not feel locked to one country, one language, or one type of user.
Clear, store-backed trust
Clear, store-backed trust
Callie does not require an account or sign-in for calculator, money, unit, percentage, or date tools. Currency conversion uses public exchange-rate requests. Free users may see non-personalized banner ads, and a one-time Remove Ads purchase is available on each platform.
The App Store and Google Play listings remain the source of truth for current privacy, ads, purchases, and availability details.
Callie Pro for iPad
Need graphing, CAS, or Python? Meet Callie Pro for iPad.
Move from graphing and Temporal Mode to symbolic algebra, local Python, Complex 3D, matrices, statistics, constants, and exports in one focused iPad workspace.
$12.99 one-time purchase in the U.S. App Store.
Download Callie
Download Callie for everyday math
Callie keeps calculator work, scientific mode, currency conversion, money tools, unit conversion, percentage math, and date tools together in one calm workspace.
FAQ
Callie FAQ
Callie is an everyday calculator and utility app for iPhone, iPad, Android phones, and Android tablets. It brings together a calculator, scientific mode, money tools, currency conversion, unit conversion, percentage math, and date tools.
Callie 2.0 includes a redesigned dark glass interface, a more intuitive workspace, a new Currency Converter with fresh daily rates, expanded 32-language support, and improved native iOS and Android experiences.
Yes. Callie includes a Currency Converter powered by public Frankfurter exchange-rate data. It supports 169 currencies, common currency shortcuts, search, swap, and cached rates after the first successful update.
Yes. Callie 2.0 supports Android phones and Android tablets, along with iPhone and iPad.
No. Callie does not require an account or sign-in for calculator, money, conversion, percentage, or date tools.
Free users may see banner ads in supported workspaces. A one-time Remove Ads purchase is available.