Calculator

Type a calculation into the launcher and the answer appears on a card above the results. There's no separate calculator mode; Redcast works out the answer as you type.

Copying the answer or putting it in the search bar also saves it to Calculator History. Only numbers, units and money go in the search bar; a date, a time or a true/false answer does not.

A single word never shows a card. On their own, tomorrow, july and pi are treated as searches.

ArithmeticCopy Anchor Link

4(2+3) is 20. 2pi, 2sqrt(9) and (2+3)(2+3) all work, and 6/2(1+2) gives the same answer as 6/2*(1+2). A lone x between numbers also multiplies, so 3x3 and $5 x 2 work. Two numbers separated only by a space never multiply, so 5 3 stays a search.

Use mod for the remainder, because % already means percent. It has the same precedence as multiply and divide, and keeps the sign of the first number: -10 mod 3 is -1.

10k is 10,000. Scientific notation works (1e5, 5e-3km, 3e+2), while 2e and 2 e mean 2 × Euler's e.

Spoken roots work with measurements: square root of 25m2 is 5 m.

A trailing operator keeps the last answer on screen. 10 + shows 10, and 10kg + 500g + shows 10,500 g, so the card doesn't flicker while you type the next number.

UnitsCopy Anchor Link

The last unit you type sets the unit of the answer.

Units written side by side form one amount. 5 feet 3 inches is 5.25 ft and 1hr 30min is 1.5 hr, answered in the first unit. These pairs are evaluated first, so 5w * 3h 30min means 5w * (3h 30min), and 90km / 1h 30min gives 60 km/h.

A number without a unit takes the unit next to it: 5kg+5 is 10 kg, and $10 + 5 is 15.00 USD.

With + and -, a percentage is relative (10kg + 20% is 12 kg). With * and /, it's a plain fraction (10kg * 3% is 0.3 kg, 10kg / 25% is 40 kg).

A unit on its own converts to a related unit: 1m gives feet and inches, and 1hr gives 60 min.

Measurements combine into area, volume, speed and more:

Results use base units unless you name a unit with to or in. Power multiplied by minutes or hours gives Wh or kWh, and current multiplied by minutes or hours gives Ah or mAh. m² and m2 both mean square meters, while (2m)^2 squares the whole amount. Use pi * (2m)^2 for the area of a circle.

to timespan splits a duration into parts: 145 mins to timespan is 2 hr 25 min. The largest part is weeks, because months vary in length.

You can only add or subtract temperatures in the same scale. Other units combine freely: 2kg / 4m3 is 0.5 kg/m³, and 1kg/m3 to g/cm3 is 0.001 g/cm³.

Volume and flowCopy Anchor Link

Cubic units range from mm³ to m³, plus in³, ft³ and yd³. You can type 3 instead of ³. Liquid measures include mL, cL, dL, L, cups, tablespoons, teaspoons, and US gallons, quarts and pints. Use fl oz for fluid ounces, because plain oz is weight. UK measures are ukgal, ukqt, ukpint and ukfloz.

ElectricalCopy Anchor Link

C means Celsius, so coulombs are shown as As. Mega and milli are case-sensitive: MW is megawatts and mW is milliwatts.

Pixels and densityCopy Anchor Link

Pixels have no fixed physical size, so include a density to convert them to inches or centimeters. The last example calculates the pixel density of a 27-inch 4K display from its diagonal.

REM and EMCopy Anchor Link

rem and em use the browser's default root font size of 16px. pt means pints, not points. When you copy a px, rem or em result, the space is removed (24px) so you can paste it into CSS.

Data and transfer ratesCopy Anchor Link

MB/s is megabytes per second and Mbps is megabits per second, so 100Mbps to MB/s is 12.5 MB/s. Binary units like MiB/s and bit amounts like kbit also work.

Other supported units include tonnes (t), stone (st), nautical miles (nmi), horsepower (hp), BTU, rpm and pound-force (lbf).

Currency and cryptoCopy Anchor Link

Redcast supports 159 currencies and a selected list of cryptocurrencies.

An amount on its own is converted to your Mac's currency. On a Mac set to Bangladesh, 1 usd shows 122.84 BDT. If you type an amount in your own currency, it's converted to US dollars, or to euros if your currency is the dollar. Your currency comes from your Mac's region setting. Redcast never asks for your location.

Words with two meaningsCopy Anchor Link

Some currency words are shared by several countries: dollars could mean 22 currencies, francs 10, pounds 9, pesos 8 and rupees 6. Redcast maps each of these to one currency. If a word is still ambiguous, Redcast shows no card. For example, krona could be Swedish or Icelandic, so Redcast doesn't guess.

Slang isn't supported: quid and bucks show no card. rmb and renminbi work, because the ISO 4217 standard names the currency "Yuan Renminbi".

Units take priority over currencies, so 10 pounds to kg is a weight, 10 pounds to euros is money, and 1 cup to ml is a volume even though CUP is also the Cuban peso. Crypto tickers take priority over words: 1 sol is Solana, while soles means the Peruvian sol.

RatesCopy Anchor Link

Rates are saved on your Mac and refreshed every 24 hours, counted from when they were saved. Restarting Redcast doesn't refresh them early, so if the saved rates are recent, opening Redcast makes no network requests.

Crypto prices are best effort. If they fail to load, currencies still work, and Redcast tries loading crypto prices again in 30 minutes.

When you're offline, the last saved rates keep working. If no rates have been saved yet, the card says so instead of guessing. A currency without a rate shows No exchange rate for <CODE>.

Money is rounded to two decimal places, or to four significant digits for amounts under a cent, and is always written out in full: 1 IDR to USD is 0.00005539 USD, never 5.539e-05.

Dates and timesCopy Anchor Link

When the answer is a date, Redcast also shows the day of the week.

till looks forward and since looks back. A date without a year uses the nearest year, so a date three days in the past means three days ago, not next year.

A number without a unit after a moment means hours after a time and days after a date: 3:45pm + 5 is 8:45 PM, and august 5 + 5 is 10 August.

Adding months and years follows the calendar: 31.1.26 + 1 month gives 28 February. + 1 day keeps the same clock time across daylight saving changes, while + 24 hours adds exactly 24 hours.

Dates with dots are day first, like 19.2.27 for 19 February 2027, and 28. aug also works. Dates with slashes are month first. Two-digit years from 00 to 68 mean the 2000s, and 69 to 99 mean the 1900s. Simple fractions like 5/2 - 1/2 are still treated as arithmetic.

WorkdaysCopy Anchor Link

weekdays, business days, work days and working days skip Saturdays and Sundays, as in today + 5 business days or 5 weekdays from now. Public holidays aren't skipped.

As a unit on its own, a workday is eight hours: 55h in workdays.

Unix timeCopy Anchor Link

now to unix gives whole seconds and now to unix ms gives milliseconds. unix 0 to date and 1000 unix ms convert back to dates. Timestamps like 2026-07-24T07:30:00+02:00 + 30min work with either a Z or an offset.

Time zonesCopy Anchor Link

If the answer falls on a different day, it says (tomorrow) or (yesterday).

Cities come from the time zone database built into macOS, plus about a hundred common cities that it doesn't include, like Salzburg or Basel. Accents are optional, so zurich works. Common abbreviations also work, like pst, cet, jst, sf, nyc and ldn, as do airport codes like lhr, nrt and sfo.

Time zone answers work offline. Redcast doesn't look up cities online.

Percent, ratios and listsCopy Anchor Link

The card labels the answer, like Tip, Discounted or Ratio, instead of a generic "Result".

Functions and comparisonsCopy Anchor Link

Functions take comma-separated values: hypot(3,4), round(3.14159,2), log(8,2), gcd(12,18), lcm(4,6), atan2(1,1), pow(2,10) and root(-8,3). There are also inverse and hyperbolic trig functions, cbrt, exp, log2, sign and trunc, and the constants tau and phi.

min, max, sum, avg, mean and average take lists, including measurements: sum(1km,500m) is 1.5 km. Inside a function, write 1000 instead of 1,000, because commas separate the values.

==, !=, <, <=, > and >= compare numbers or compatible units: 1km == 1000m is true. Whole numbers support &, |, xor, ~, << and >>. ^ always means a power.

Base conversion works both ways: 0xff shows Hexadecimal → Decimal, and 2m / 2m to hex is 0x1.

ErrorsCopy Anchor Link

The calculator only shows an error for real mistakes, like combining two units that don't fit together (1kg + 1m) or a unit and a currency (Cannot convert Currency to Weight.).

For anything else, it shows nothing rather than flashing an error while you're still typing.

Calculator HistoryCopy Anchor Link

Calculator History is a separate screen that you open with the command of the same name. It isn't part of the tab cycle. To leave it, press esc, or delete in an empty search.

ColorsCopy Anchor Link

Paste a color like #FF5733, rgb(255, 87, 51) or hsl(11, 100%, 60%) into the launcher and a card shows the color. ⌘K lets you copy it as hex, rgba(), hsl() or oklch().