Multi-Base Calculator

The Ufumbuzi Multi-Base Calculator is a calculator and converter for people who work with numbers that are not decimal. It calculates in binary, octal, decimal, hexadecimal, base 32, base 64 and custom bases from 2 to 36, and shows the same value in every base at once. The keypad changes with the selected base: binary only shows 0 and 1, hexadecimal shows 0–F, and base 64 shows its 64 symbols.

What it does

• Converts as you type. Enter a value in the current base and the conversions panel updates immediately with its binary, octal, decimal, hexadecimal, base 32, base 64 and custom-base equivalents.
• Calculates in the selected base. Add, subtract, multiply, divide and take modulo without converting the operands by hand. The result stays in the base you are using.
• Keeps large integers exact. Integer conversion, addition, subtraction, multiplication and modulo use exact arithmetic, so a long binary result is the real value instead of a rounded approximation.
• Uses decimals where they make sense. Fractions work in binary, octal, decimal, hexadecimal, base 32 and custom bases. Results show up to eight digits after the point. Base 64 is integer-only.
• Includes bitwise logic. AND, OR, XOR and NOT work on integer values, which is useful for masks, flags and low-level programming.
• Copies any result. Every conversion row and the main display have a copy button, so a value can go straight into code, a configuration file or a message.

A keypad that matches the base

The keypad is not a fixed decimal keypad with empty holes. It is rebuilt for the base you choose. Binary shows only 0 and 1; octal shows 0–7; decimal keeps the familiar 7–8–9 order; hexadecimal shows 0–9 and A–F; base 32 shows 0–9 and A–V; and base 64 shows all 64 symbols. Custom bases show only the digits they use, so the keypad stays compact and there is no need to scroll sideways to find a character.

The operators live in a separate row, which matters in base 64 because + and / are also digits. The two symbol keys in the digit pad enter those digits, while the operator buttons perform addition and division. On a physical keyboard, + and / are treated as operators; use the on-screen digit keys when you need those base-64 symbols.

Large binary results without layout jumps

A binary representation grows quickly. A decimal number with twenty digits can produce a binary string with more than sixty characters. Instead of wrapping that string into several lines and pushing the keypad down, the calculator keeps the display and every conversion on a single scrollable line. The keypad stays where it is, even when the result is hundreds of characters long.

This is useful on phones and small laptop screens, where a wrapped binary row used to move the buttons below the visible area. The conversions panel also has a fixed maximum height and scrolls inside its own card, so a long number never changes the page layout.

Base 64 is a number base here

Base 64 in this calculator is a positional number base that uses the symbols 0–9, A–Z, a–z, + and /. It is not MIME Base64 encoding or decoding of files and text, and it does not add = padding. If you need to encode binary data for JSON, email or a URL, use a dedicated Base64 encoder.

Because base 64 is a number base here, it works with integers only. Choose another base if you need fractions. The app explains this in the help panel so the distinction is clear before you start a calculation.

Practical uses

Programmers use the calculator to check bit masks, permissions, memory addresses, color values and protocol fields. Octal is common in Linux permissions, hexadecimal appears in colors and memory dumps, and binary is the reference for bitwise operations. Students can use it to check conversions while learning how positional number systems work.

For example, a Unix permission such as 755 in octal can be read next to its binary and hexadecimal forms, and a hexadecimal color value can be checked against its decimal channels. The same value is always visible in every base, so there is no need to repeat the conversion in separate tools.

Limits and details

• Base 64 works with integers only. Fractions are available in every other base.
• Fractional results show up to eight digits after the point and use floating-point arithmetic. Integer operations remain exact.
• Bitwise operations work on integer values, but this is not a fixed-width 8-bit, 16-bit, 32-bit or 64-bit simulator.
• Operations are calculated immediately from left to right, like a pocket calculator. There are no parentheses, operator precedence, memory keys, history or scientific functions.
• Custom bases cover 2 to 36. Base 32 and base 64 are ready-made presets.

Offline, private and free

The calculator is a progressive web app. After the first load it works without a connection, and it can be installed on a phone or desktop. All calculations run in the browser: there is no account, no advertising and no upload of the numbers you enter. The app is free and does not require a sign-up.

If you need ordinary arithmetic with units, the unit converter is the better fit. If you need to read a scanned code, the code scanner turns it into text.

Linux: a .deb package is listed in the Linux downloads section.