calced 0.1.0

A notepad calculator that evaluates expressions in text files

calced

A notepad calculator that evaluates math expressions in plain text files. Available as a CLI tool and a web app — both use the same syntax and are validated against the same test suite.

Web

Open the web app in a browser — no install required.

CLI

calced <file>           # evaluate and update file in place
calced -s <file>        # print result to stdout (don't modify file)
calced -w <file>        # watch for changes and auto-update
calced -w -s <file>     # watch and print (clears screen on change)

Installation

Requires Python 3.9+.

# With uv (recommended)
uv tool install ./python

# Or just run the script directly
python python/calced.py <file>

How it works

Write math anywhere in a plain text file. Results are appended inline as # => result comments. Non-math lines are left untouched.

rent 1500                               # => 1_500
groceries 200 + 150                     # => 350
utilities 80 + 45 + 30                  # => 155
total                                   # => 2_005

Results are aligned and updated in place each time you run the CLI (or automatically in watch mode), or live as you type in the web app.

Features

Basic arithmetic

2 + 3                                   # => 5
10 * (4 + 6)                            # => 100
2 ^ 10                                  # => 1_024
17 % 5                                  # => 2

Variables

income = 5000                           # => 5_000
tax_rate = 22%                          # => 0.22
tax = income * tax_rate                 # => 1_100
after_tax = income - tax                # => 3_900

Percentages

50% of 300                              # => 150
200 + 15%                               # => 230
200 - 10%                               # => 180

SI prefixes

1k                                      # => 1_000
1M                                      # => 1_000_000
1.5G                                    # => 1_500_000_000
500n * 2                                # => 0.000001

Supported: k/K (kilo), M (mega), G (giga), T (tera), P (peta), E (exa), m (milli), u/μ (micro), n (nano), p (pico), f (femto), and more.

Unit conversions

5 km in miles                           # => 3.11
100 C in F                              # => 212
1 gib in mib                            # => 1_024
60 min in hr                            # => 1
1 gal in l                              # => 3.79

Supported dimensions: length, mass, temperature, data, time, volume. Use in or to.

Functions

sqrt(16)                                # => 4
round(3.14159, 2)                       # => 3.14
min(5, 2, 8)                            # => 2
max(1, 9, 3)                            # => 9
log10(1000)                             # => 3
sin(0)                                  # => 0

Available: sqrt, abs, floor, ceil, round, log, log2, log10, sin, cos, tan, asin, acos, atan, exp, min, max

Constants

pi * 2                                  # => 6.28
e ^ 1                                   # => 2.72

Totals

The total (or sum) keyword sums all numeric results since the last # heading or start of file.

rent 1500                               # => 1_500
groceries 350                           # => 350
utilities 155                           # => 155
total                                   # => 2_005

Blank lines are ignored in the total; headings reset it.

Number formats

Numbers can be written with commas or underscores as separators (1,000 or 1_000), in hex/binary/octal (0xFF, 0b1010, 0o77), or in scientific notation (1.5e3).

Trailing annotations

Parenthetical notes after an expression are ignored:

celo_price = 0.08 (see http://coinmarketcap.com)  # => 0.08

Format directives

Control output formatting with @format and @separator directives. These apply to all subsequent lines until changed.

1000000                                 # => 1_000_000
@format = fixed(2)
1000000                                 # => 1_000_000.00
@format = scientific
1000000                                 # => 1.00e+06
@separator = comma
@format = minSig(3)
1000000                                 # => 1,000,000