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Convert ancient Persian length units: parasang, royal cubit, cubit, pace and more — to metric and imperial.
Convert ancient Persian weights: karsha, shekel, mina and talent — to grams, kg, pounds and ounces.
Convert ancient Persian volume units: artaba and griw — to liters, gallons and quarts.
Convert ancient Greek length units: pous, daktylos, palaiste, pechys, stadion and parasang — to metric and imperial.
Convert ancient Greek weights: drachma, obol, mina and talent — to grams, kg, pounds and ounces.
Convert ancient Greek volume units: medimnos, choinix and kotyle — to liters, gallons and quarts.
Convert ancient Roman length units: pes, digitus, uncia, cubitus, passus and mille passus — to metric and imperial.
Convert ancient Roman weights: libra, uncia and scrupulum — to grams, kg, pounds and ounces.
Convert ancient Roman volume units: modius, sextarius, congius and amphora — to liters, gallons and quarts.
Convert biblical length units by halachic opinion: Chazon Ish, R. Chaim Naeh or Rambam — amah, tefach, etzba, mil, parsah.
Convert biblical weight units: shekel, bekah, gerah, maneh and kikar (talent) — to grams, kg, pounds and ounces.
Convert biblical volume units: ephah, bath, hin, seah, omer, kav and log — to liters, gallons and quarts.
Convert Japanese length units: shaku, sun, ken, cho and ri — to metric and imperial.
Convert Japanese weights: monme, kin and kan — to grams, kg, pounds and ounces.
Convert Japanese volume units: sho, to and koku — to liters, gallons and quarts.
Convert Chinese weights: jin (catty), liang (tael) and qian (mace) — to grams, kg, pounds and ounces.
Convert Chinese volume units: sheng, dou and dan — to liters, gallons and quarts.
Convert old Russian length units: arshin, sazhen, versta, pyad and vershok — to metric and imperial.
Convert old Russian weights: pud, funt, zolotnik and berkovets — to grams, kg, pounds and ounces.
Convert old Russian volume units: vedro, shtof, chetverik, osmina and chetvert — to liters, gallons and quarts.
Compute your semester GPA on the standard US 4.0 scale. Add courses, set letter grades and credit hours — the weighted GPA updates instantly.
Calculate tip, total, and each person’s share instantly. Adjust the tip percent, split the bill any number of ways.
Calculate sale prices, savings, and stacked discounts instantly. Add a coupon discount and sales tax to see the final out-the-door price.
Find your exact age in years, months and days. See your next birthday countdown, day of the week you were born, and total days alive.
Generate strong random passwords in your browser. Cryptographically secure, nothing is uploaded.
Check if your password appeared in a data breach. Your password never leaves your browser.
Calculate your monthly mortgage payment, total interest, and how much extra payments save you.
What is X% of Y? X is what percent of Y? Percent increase and decrease — answered instantly.
How many days between two dates? What date is 90 days from now? Answered instantly.
Convert millimeters, centimeters, meters, kilometers, inches, feet, yards and miles instantly.
Convert Celsius, Fahrenheit and Kelvin instantly, with common reference points.
Convert bytes, kilobytes, megabytes, gigabytes and terabytes. Explains KB vs KiB.
What score do you need on your final exam to get an A? Enter your grade, the final weight and your target.
What time should you go to bed? Wake up at the end of a 90-minute sleep cycle and skip the grogginess.
What time is it in London when it is 3pm in New York? Convert any time across time zones, DST handled.
Unscramble letters into every real word they can make — grouped by length, with Scrabble scores. For Scrabble, Words With Friends, crosswords and anagrams.
Stuck on Wordle? Enter your green, yellow and gray letters and see every five-letter answer that still fits, ranked most likely first.
Sunrise and sunset times for any place and date, with dawn, dusk, golden hour, solar noon and day length — computed from the sun's real position, no weather feed needed.
Pick a star, a place and a date: see when it rises, when it passes highest in your sky (transit), and when it sets — with compass directions and tonight's position.
The exact time, live: a clock synchronized to an internet time server with millisecond display, UTC time, day of year, ISO week and Unix timestamp.
A live planetarium and solar-system simulator: the real positions of the Sun, Moon, all eight planets and 493 named stars for any place, date and time — watch oppositions and moon phases happen.
Tonight’s star map for your place and time, with the twenty stars most worth watching — doubles, variables and giants — marked, with their stories.
What do your dreams mean? A traditional dream dictionary of 70+ symbols — snakes, water, teeth, flying, falling — with the classical interpretations from Artemidorus to the old almanacs.
The classic TRUE LOVE name test: enter two names and get your compatibility percentage, with the full calculation shown — plus a zodiac reading if you add birthdays.
A 20-question personality test based on the Big Five model psychologists actually use: openness, conscientiousness, extraversion, agreeableness and emotional steadiness — with your profile explained.
Ten everyday scenarios reveal your friendship style: the Loyal Rock, the Cheerleader, the Truth-Teller or the Adventurer — which friend are you?
Most calculator sites are slow, covered in ads, and look like 2005. CalcHub is a single fast page per calculator: type your numbers, get the answer instantly. Everything runs in your browser — nothing is uploaded or tracked. New calculators are added every week, so if the one you need is missing, check back soon.