I hate cooking math. So I built a smart Android calculator.

kuroappworks — Thu, 05 Mar 2026 14:28:38 +0000

I love cooking, but I've always been terrible at the math.

Whenever a recipe calls for a "1:14 ratio" or "5x dilution," I find myself staring at a measuring cup, trying to figure out exactly how many milliliters of water I actually need.

I didn't want to stop my flow in the kitchen just to do mental arithmetic. So, I decided to build a calculator with automated functions that solve kitchen math, microwave conversions, and more—instantly.

What I Built

EveryCal is a simple yet powerful calculator for Android.

Beyond standard operations, I packed it with features designed for multitasking. It features real-time results as you type, a handy memo function for shopping lists, a floating calculator that overlays on other apps, and even voice input—so you can just say "Microwave" when your hands are covered in flour.

The Feature Breakdown

1. Smart Cards: Instant Solvers for Daily Life

I grouped common calculations into card formats for different scenarios: kitchen, shopping, and travel.

Dilution & Concentration: Auto-calculates ratios and percentages. Perfect for mixing seasonings or DIY sanitizers.
The Microwave Converter: Converts recipe wattage (e.g., 600W to 500W) to match your home microwave.
Smart Shopping: Compare unit prices to find the best deal and calculate discounts to avoid "checkout anxiety."
Global Utilities: Includes real-time currency exchange, unit conversion (Imperial to Metric), and even Japanese/Western calendar conversion.

You can summon any of these cards just by saying keywords like "Microwave" or "Exchange." I've implemented 19 of these automated solvers so far.

2. Memo Feature: Say Goodbye to Forgotten Items

A quick-access memo pad with a checklist mode. Tap to cross off items as you shop—simple and effective.

3. Floating Calculator: No More App Switching

Need to calculate while reading a recipe in your browser or scrolling SNS? You can keep a mini-calculator pinned to the corner of your screen.

4. Advanced Workspace

For the power users, the "Custom Workspace" lets you pin only the cards you use most. And yes, all the basic calculator functions like constant and percentage math are solid.

The Tech Stack

EveryCal is built with a modern Android stack:

Language: Kotlin
UI Framework: Jetpack Compose
Database: Room (for memos and history)
Networking: Retrofit (for live exchange rates)
Async: Coroutines & Flow
DI: Manual Injection (keeping it lightweight)
Parser: exp4j (for formula expression parsing)

Get It Now

If you want to stop doing manual math and start getting things done, check out the manual or grab the app on the store.

Official Manual: EveryCal Manual
Google Play Store: Get it on Google Play

Forem: kuroappworks