Twin Calculator

Two independent calculators side by side in your side panel — keep two running totals without losing either.

🔢 Twin Calculator — Two calculators side by side, always in your sidebar A single calculator is never the problem. The second number is. Twin Calculator lives in Chrome's Side Panel and gives you two independent calculators, A and B, stacked one above the other. Add up one column, add up the other, and neither one disturbs the other — no scratch paper, no second tab, no re-typing. ✨ Key Features: • 🔢 Two Full Calculators — A and B each have their own keypad, their own display, and their own running operation. Nothing you type in one disturbs the other, and one tap swaps them. • 💰 Made for Money — Dedicated 00 and 000 keys, because amounts have zeros: tap 35 then 000 and you have 35,000. Thousands separators are always on, so you never count digits to check whether that's 35,000 or 350,000. • 📊 Both Totals in View — A and B stay pinned to the top of the panel, so you can still see one while you're working down in the other. • 📜 History — Your last 50 results, each with the expression that produced it. Tap a number to copy it, or load it straight back into the calculator it came from. • ⌨️ Real Keyboard Input — Type with your number keys, + - * /, Enter, Backspace and Esc. Typing goes to whichever calculator has focus. • 🌐 8 Languages — English, 한국어, 日本語, 简体中文, Español, Français, Deutsch and Português (BR). Digit grouping and the decimal separator follow your browser language too, so you get 1,234.5 or 1.234,5 as you'd expect. • 🎨 12 Theme Colors — Light, dark, or automatic by time of day, with eight rich accents and four pastel ones. • 🔒 100% Private — Everything stays on your device. No accounts, no tracking, no network requests at all. Works fully offline. 🎯 Perfect for: • Keeping a cost and a price side by side • Weighing option A against option B while shopping or quoting • Adding up two separate running totals without losing either • Anyone who keeps a calculator and a notepad open just to hold two numbers at once 💡 How to use: Click the Twin Calculator icon to open it in your sidebar. Type into calculator A, then into calculator B — both totals stay visible at the top as you go. Switch the bottom section to History to pull an earlier result back in. Install Twin Calculator and stop losing your second number.