Sizu Home › Calculators › The Daily Multiplier
Opens on the book's Microgreen Shelf. Change any number to your own and press Calculate.
Rates: a month and a year, both ways (leave blank to skip)
Enter a start, an end and the number of steps, then press Calculate.
The formula
- Multiplier per step = (end ÷ start)1/steps: the steps-th root
- Percent per step = (multiplier − 1) × 100
- Yearly from monthly = (1 + monthly)¹² − 1, never monthly × 12
- Monthly from yearly = (1 + yearly)1/12 − 1
The book's worked example, Chapter 4. Radish: 28 g to 280 g in 9 days, 101/9 = 1.2915 a day. Broccoli 1.3, sunflower 1.17, pea 1.04: a 1.04 crop is not a bad crop, it brings most of its weight in with the seed. A loan at 1.5% a month is 19.56% a year, not 18%; 3% a year is 0.2466% a month.
Check it. Multiply the start by the multiplier as many times as there are steps: you should land on the end. The ladder's last line does it for you.
Honest limits. One multiplier for every day is a model: a real tray grows slowly at first, fast in the middle and slowly at the end (Chapter 5's S-curve). The Microgreen Shelf was worked out on paper from published figures, not grown by us: weigh and measure your own. Prices are illustrative US prices from October 2026, shown without a currency sign; put in your own. Everything stays in your browser: no sign-up, nothing stored.
These calculators go with Grow by Numbers (Make It Add Up, Book 1), where every number on this page is worked by hand.