Absurd questions, taken seriously.
How much energy does the rush-hour subway squeeze out of your ribcage? If a paycheck literally fell from the sky, how would the IRS classify it? Let's Calc runs everyday absurd questions through math, physics, economics, law, and statistics — and shows the working.
Calculations grounded in physics, chemistry, biology, and the wider natural sciences
9 calculationsCalculations involving prices, markets, taxes, debt, inflation, and economic intuition
8 calculationsCalculations about the absurd questions that pop up in daily life
21 calculationsCalculations through the lens of law, policy, sociology, and statistics
5 calculationsCalculations about human biology, calories, sleep, exercise, and medicine
3 calculationsCalculations that zoom out to the planetary, galactic, or otherwise jaw-dropping scale
8 calculations
A dishwasher uses less water, but who wins on cost and carbon? We compare it with frugal hand-washers (UK measurement) and average ones (German experiment), with gas or electric hot water and different loads, and work out how many days a single person should wait before running a load.
We build up the cost of one Incheon–Los Angeles flight line by line, then split it by the floor area each seat actually occupies. How many of the 269 seats have to sell before the airplane breaks even — and does business class really cover the flight on its own?
We count everything from building and furniture doors to bacterial flagellar motors, one category at a time, using Merriam-Webster as the only ruler. The lead changes hands three times, and the shakiest reversal comes down to how many Hot Wheels cars are still rolling around somewhere.
How much does the same Hyundai Elantra (the Avante in Korea) really cost over five years — bought new, bought as a 3-year-old used car, or on a 60-month long-term rental? This piece breaks down exactly what the lease's ₩49,021 (≈$34) monthly premium over buying new actually buys — depreciation uncertainty, breakdown risk, upfront capital — and finds the new-vs-used race, a ₩1.27M gap in cash terms, closes to a mere ₩9,193 once real financing rates enter the picture.
Guess your way through all 45 questions on the Korean-language section of Korea's CSAT and the math says you'll land near 20 points, with a standard deviation of 6.07. But the odds of a flat zero sit in the exact same statistical neighborhood as the odds of scoring 47 or higher. The probability of a perfect 100 is 3.52×10⁻³² — 8,158 times the age of the universe, even with 8 billion people guessing once a second. The twist: that terrible probability comes from question count, not difficulty, until real perfect-scorer data reveals the actual culprit is a handful of killer questions. Run the same math on the redesigned ACT and the odds get even more absurd.
The Book of Joshua describes six days of marching once around Jericho's walls, then seven laps on the seventh — 13 laps in all. How far did that add up to for one person, how long did it take, and how much metabolic energy did 40,000 marchers burn doing it? We reverse-engineer the city's size from archaeology, weigh three guesses at how far back from the wall they actually walked, and convert the total into joules — and, just for scale, into tons of TNT.
One avocado (100 g flesh) gets dissected through three lenses: water, carbon, and nutrition efficiency. The math checks the popular "200-320 liters of water" claim against the primary dataset, tests how much transport mode swings the carbon footprint, and ranks avocado's nutrient-per-liter efficiency against four other fruits.
A car's sticker price is just the opening bid. Add in fuel, insurance, registration tax, maintenance, and resale value, and the total cost of ownership (TCO) tells a very different story. We run the numbers on a Hyundai Tucson in gasoline, diesel, and hybrid trims plus an IONIQ 5 EV — and the cheapest car changes not once but twice as ownership length and annual mileage shift.
Let's Calc takes everyday absurd questions and oddball hypotheticals seriously. Each post draws on math, physics, economics, law, or statistics, and follows the signature [INPUT] / [FORMULA] / [OUTPUT] format — assumptions stated, working shown, punchline at the end.
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