The Meaning of Life Calculator
Think of any number, or any word. The answer is always 99, and here is the proof.
Good to know. Deep Thought took 7.5 million years to answer 42. It was off by 57.
Try to break it. Found an input that isn’t 99? That’s the 1%. Tell us.
Now try a real one
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How it works
In plain words
Double your number, add 198, divide by 2, then take away the number you started with. Halving undoes the doubling and turns the 198 into 99, and taking away your number removes the only part that was ever yours.
The formula
(2x + 198) ÷ 2 − x = x + 99 − x = 99
Worked example
Start with 42, the famous answer to everything. Doubled it is 84, plus 198 is 282, halved is 141, and 141 − 42 = 99.
Sources
- Douglas Adams, The Hitchhiker’s Guide to the Galaxy, 1979
Sources checked September 29, 2026. 7 automated tests check its answers on every change.
About the meaning of life calculator
This is the classic "think of a number" trick, done properly. Whatever number you pick, doubling it, adding 198, halving and then taking away your number always lands on 99. The table under the result shows every step with your own number, so you can check the arithmetic yourself.
Why does it work? Write your number as x. Doubling gives 2x, and adding 198 gives 2x + 198. Dividing by 2 gives x + 99: the halving cancels the doubling and turns 198 into 99. Taking away x leaves 99, and x never had a say. The same algebra holds for negative numbers, decimals and numbers with hundreds of digits, and the steps here are worked out exactly rather than rounded, so even huge inputs come out at exactly 99.
Words work too. Each letter gets its place in the alphabet (a = 1, b = 2, up to z = 26) and the letters are added up, so "banana" becomes 33. Accented letters count as their plain versions. Text without any letters, like a row of emoji, counts its characters, and an empty box counts as 0.
To use it as a trick on a friend, let them pick the number in secret and read the steps out loud. Or just send them the link with their name in it.
Questions people ask
Does it really give 99 for every number?
Yes. (2x + 198) ÷ 2 − x simplifies to 99 for any x, and the steps here use exact arithmetic, so there is no rounding to spoil it.
How does a word become a number?
Each letter counts as its place in the alphabet, a = 1 to z = 26, and the letters are added up. "Cat" is 3 + 1 + 20 = 24.
Why 42?
In The Hitchhiker’s Guide to the Galaxy, 42 is the answer to life, the universe and everything. We think 99 is a rounder answer. The math agrees.
Can I make it land on a different number?
Yes. Add twice your target instead of 198. Adding 20, for example, always lands on 10.