Table of Contents

Quick Start

Numi supports many units, and allows to easily convert one into another like $20 in Euro or 20 cm in inches. When it's needed, Numi will convert units automatically, like in 20 CAD + 4 Euro + 5 GBP.

You can easily convert time between time zones and get current time in different locations like Seoul time or now in Germany.

Numi supports word operations, scales and different numeral systems. So you can calculate 3 times 4 or use $1k instead of $1000 and convert 240 to hex. App allows to set variables, like var = $20 - 5%. Numi also supports tokens for operations like sum for sum of all results above or prev for the result on the previous line.

Numi supports many mathematical functions, constants and friendly percentage functions like 20% of $10 or 5% of what is 6 cm. Numi allows you to format your calculations with labels, comments and headers. Use special shortcuts to improve your calculation typing, like ⇧⌘0 for surrounding with parentheses.

Numi is absolutely free in beta, and perhaps will be free after release with some pro functionality for the price of few latte cups.

Unit Conversion

With in (into, as, to) you can convert one unit into another:

$30 in Euro

Numi will automatically convert units to perform operations if it's needed.

$30 CAD + 5 USD - 7EUR

In the first step all values will be converted to the Euro, then the addition will be performed.

Time Zone Conversion

Use time or now function to get time in your time zone. You can prefix this functions with time zone location (or use in with time zone suffix) to get current time for specified location:

PST time
New York time
Time in Madrid
Now in Seoul

Results are always in sync with global time, so, at any point of time you will get the right time.

It's also possible to convert specific time or date from one time zone into another. Or calculate difference between time in different time zones:

2:30 pm HKT in Berlin
13:30 PST in local
Madrid time - Los Angeles time


You can use sign and word operators.

$7 × 56
8 times 9
Operation Sample
Addition +, plus, and, with
Subtraction -, minus, subtract, without
Multiplication *, times, multiplied by, mul
Division /, divide, divide by
Exponent ^
Bitwise And &
Bitwise Or |
Bitwise Xor xor
Left Shift <<
Right Shift >>
Modulo mod

Several expressions might be stacked together:

1 meter 20 cm = 120 cm

Expressions will be multiplied if used in parentheses:

6 (3) = 18


Besides decimal numeral system, it is possible to use numbers in binary, octal or hexadecimal form using appropriate prefix: 0b, 0o and 0x. You can change output as well:

0o1435343 in hex
0xfff in bin

You can use sci or scientific to format results in scientific notation:

5 300 in sci


You can use ISO 4217 codes for currency (like USD, RUB, CAD etc). You can also use common currency names and signs, like $ for the US dollars, roubles for Russian roubles, or for Euro.

Numi updates currency rates several times a day using open exchange rates service.


In addition to general percentage operations like adding or subtracting percent of value ($10 - 40%), you also can use additional operations:

Operation Example
Percentage value 20% of $10
Adding percentage 5% on $30
Substracting percentage 6% off 40 EUR
Percentage value of one value relative to another $50 as a % of $100
Percentage addition of one value relative to another $70 as a % on $20
Percentage subtraction of one value relative to another $20 as a % off $70
Value by percent part 5% of what is 6 EUR
Value by percent addition 5% on what is 6 EUR
Value by percent substraction 5% off what is 6 EUR


Scales used for shorter form of writing big numbers. For instance, instead of typing $2000 you can use shorter variant:


Please note that one-letter scales are case-sensitive, since m used for meters, and K used for Kelvins. Supported scales:

  • Thousand: k, thousand
  • Million: M, million
  • Billion: billion


You can declare variables and reuse them using the = operator. Please note some characters and keywords cannot be used as a variable. For example, K might be used as a temperature unit in Kelvin. Variable names should not contain whitespaces or special characters, and should not start with number:

v = $20
v2 = 5% 
v times 7 - v2
v += $10


Description Value
Pi 3.1415926536
E 2.7182818285


By default trigonometrical functions uses parameters in radians.

Description Function Example
N-th root root root 2 (8)
Square root sqrt sqrt 16
Cubed root cbrt cbrt 8
Absolute value abs abs(-4)
Logarithm log log 2 (10)
Natural logarithm ln ln 3
Factorial fact fact 5
Rounding round round 3.45
Ceiling ceil ceil 3.76
Flooring floor floor 2.56
Sine sin sin 45°
Cosine cos cos 3.45
Tangent tan tan 8
Arcsine arcsin arsin 30
Arccosine arccos arccos 85
Arctangent arctan arctan 9
Hyperbolic sine sinh sinh 3
Hyperbolic cosine cosh cosh 9
Hyperbolic tangent tanh tanh 11


Numi supports several CSS units:

  • pixels (px)
  • points (pt)
  • em

For example:

12 pt in px

Em is set to 16 px by default, but you can assign different value:

em = 20px
1.2 em in px

Conversion from screen units to other length units performed using pixel per inch value (ppi). By default ppi is set to 96 pixels, which mean in every inch there're 96 pixels:

1 inch in px = 96 px

You can set custom value for ppi. For instance, here is calculation for iPhone 6 with ppi = 326:

ppi = 326
1 cm in px = 128,35 px


Tokens are special sort of variables. They are useful when you want to reuse result from previous line or calculate sum above.

Previous Result

Use prev token to use result from previous line:

Cost: $20 + 56 EUR
Discounted: prev - 5% discount


You can calculate sum of all lines above (until empty line) using sum ( total ) operator.

Line 1: $10
Line 2: $15
Result: sum


You can calculate an average of all lines above (until empty line) using average ( avg ) operator.

Line 1: $10
Line 2: $20
Result: average


You should be able to use any form of the units: short, long, abbreviation. If you can't use some form of unit, please, write us.

SI based units support all SI prefixes, both short and long form. Note that SI prefixes are case-sensitive. For example, use MB for megabytes, not mB:

1 mm
2 picometers
3 GB

Date & Time

To make time calculations more straightforward, 1 year is equal to 365 days, and 1 month equal to 1/12 of the year. In cases where results give non-integer value, round functions might be used to make an integer:

round(1 month in days)

Supported units: Second, minute, hour, day, week, month, year

Use fromunix function to convert timestamp into dates:



Kelvin, celsius, fahrenheit


Meter, mil, points, lines, inch, hand, foot, yard, rod, chain, furlong, mile, cable, nautical mile, league

Since in is used as a conversion operator, you cannot use it for inches.


Hectare, are, acre

It is possible to use all length units with square or sq prefix

20 sq cm
30 square inches
11 sqm


Pint, quart, gallon, tea spoon, table spoon, cup

It is possible to use all length units with cubic, cu or cb prefix

20 cu cm
30 cubic inches
11 cbm


Gram, tonne, carat, centner, pound, stone, ounce


Radian, degree

You can use both as text form of unit (radians, degrees) as sign. For example, 45 °


Bytes multiplies contain 1000 bytes. If you need 1024 multiplier, use kibibytes. Please note lowercase b is used for bits, and uppercase B for bytes.

Bit: b, bit, kb, kib, kilobits, mb, ... Byte: B, byte, kB, kiB, megabyte, ...


Use hash symbol at the beginning of the line to make a header:

# This is header

If you want to comment part of the line, use double quotes:

$275 for the "Model 227"

To comment all line, use double slash:

// This is comment

Use colon to make a label (label will not be evaluated):

Price: $11 + $34.45


Text editing

Surround with parentheses ⇧⌘0
Copy result on current line ⇧⌘C
Select all ⌘A
Delete all ⎇⌘⌫
Copy all ⎇⌘C


Import ⌘O
Export ⌘S
Print ⌘P

Import & Export

Numi does not modify imported files until you explicitly export them. All exported files have .numi extension. You can open .numi files with any text editor since Numi uses plain text and UTF-8 encoding to store files.


Numi uses crowdsource model for translation. That means anyone can participate in translation process.

  • Sign up on the One Sky translation service
  • Take a look at current state of translation for your language. Can't find it there? Contact us
  • Start translating. You can filter for all untranslated phrases in interface, for example.