Decimal Point & Thousands Separators

Notes Calculator reads numbers written with thousands separators the same way it shows them, so you can type — or paste back — a grouped number like 1.234.567 and get its value.

Which character is the decimal point and which is the thousands separator is controlled by the Use dot as decimal point setting.

The two conventions

Setting	Decimal point	Thousands separator	Example input	Value
Off (default)	`,` comma	`.` dot	`1.234.567,89`	1234567.89
On	`.` dot	`,` comma	`1,234,567.89`	1234567.89

With the default setting — comma is the decimal point, dot groups the thousands:

1.234.567                              | 1.234.567
1.234.567,89                           | 1.234.567,89
18,5                                   | 18,5
2 * 1.234.567                          | 2.469.134

With Use dot as decimal point turned on — dot is the decimal point, comma groups the thousands:

1,234,567                              | 1,234,567
1,234,567.89                           | 1,234,567.89
18.5                                   | 18.5

Rules

Thousands groups are three digits each (the leading group may be 1–3). A well-formed number like 1.234.567 is read as 1234567; a malformed one like 1.2.3 is not a valid grouped number and is simply ignored (the line stays blank).
A single separator is always the decimal point, never a group. So 1.234 is 1.234, not 1234 — a lone separator can’t be told apart from a decimal point, so it is treated as one.

Underscores for readability

You can also group the digits of a whole number with underscores — the same trick many programming languages use. Underscores are purely visual, so they work the same way whatever your decimal-point setting is:

1_000_000                              | 1.000.000
123_456_789                            | 123.456.789
2 * 1_000                              | 2.000

An underscore has to sit between two digits — a leading, trailing, or doubled underscore (_1000, 1000_, 1__000) isn’t a valid number, so the line just stays blank. Underscores group the whole-number part only; they aren’t read inside the decimal part or an exponent.

Inside functions, commas separate arguments

A comma is also how you separate function arguments, so a comma inside a function call is treated as an argument separator — not a thousands group:

sum(100, 200, 300)                     | 600

With Use dot as decimal point on, sum(1,234,567) is therefore read as the three arguments 1, 234, 567 (which sum to 802), not as one grouped number. To pass a grouped number as a single argument, wrap it in parentheses:

sum((1,234,567), 3)                    | 1,234,570