Home › Calculators › Rough vs Exact: How Far Off?
Opens on Chapter 1’s example: Uncle Dez’s envelope estimate of 1,000 hours for the office move, against Hana’s spreadsheet’s 1,137.5.
Enter your numbers, then press Calculate.
From the book, Chapter 1. Dez’s 1,000 hours was 12% low. An estimate of 600 against a true 1,000 is 40% low, a factor of 1.67; 3,000 against 1,000 is 200% high, a factor of 3.
Rounding is half up, the way the book rounds. Numbers can be typed as 1,450, $38, 12%, 1/20, 2.5 million or 3 × 10⁷. Everything stays in your browser: no sign-up, nothing stored or sent.