Tools
Free grow
calculators.
Free tools built on the same science as our articles. No sign-up, in °C and °F.
FreeNo sign-up°C and °FFormulas and sources shown
VPD calculatorLeaf VPD, dew point and the humidity to target for clones, veg and flower.Open the calculator ›DLI calculatorTurn PPFD and hours of light into DLI and find the PPFD each stage needs.Open the calculator ›Harvest date calculatorThe expected harvest window and when to start trichome checks, with a calendar reminder.Open the calculator ›Cost per gram calculatorElectricity, nutrients and equipment against your dry yield, with a full cost breakdown.Open the calculator ›
Every calculator explains the formula behind it and links to the full guide in our Science section. Numbers get you close; the plant has the last word, so read the trichomes before you chop.